diff --git a/.changes/next-release/enhancement-Migration-48043.json b/.changes/next-release/enhancement-Migration-48043.json
index 562578687c30..ad42ffc841a3 100644
--- a/.changes/next-release/enhancement-Migration-48043.json
+++ b/.changes/next-release/enhancement-Migration-48043.json
@@ -1,5 +1,5 @@
 {
   "type": "enhancement",
   "category": "Migration",
-  "description": "Implement a ``--migrate-v2`` flag that detects breaking changes for AWS CLI v2 for entered commands."
+  "description": "Implement a ``--v2-debug`` flag that detects breaking changes for AWS CLI v2 for entered commands."
 }
diff --git a/awscli/clidriver.py b/awscli/clidriver.py
index 1a798aa2c5c0..07d12131af68 100644
--- a/awscli/clidriver.py
+++ b/awscli/clidriver.py
@@ -41,7 +41,6 @@
 )
 from awscli.commands import CLICommand
 from awscli.compat import get_stderr_text_writer
-from awscli.customizations.utils import uni_print
 from awscli.formatter import get_formatter
 from awscli.help import (
     OperationHelpCommand,
@@ -49,7 +48,7 @@
     ServiceHelpCommand,
 )
 from awscli.plugin import load_plugins
-from awscli.utils import emit_top_level_args_parsed_event, write_exception, create_nested_client
+from awscli.utils import emit_top_level_args_parsed_event, write_exception, create_nested_client, resolve_v2_debug_mode
 from botocore import __version__ as botocore_version
 from botocore import xform_name
 
@@ -682,7 +681,7 @@ def _detect_binary_file_migration_change(
             # if cli_binary_format is set to raw-in-base64-out, then v2 behavior will
             # be the same as v1, so there is no breaking change in this case.
             return
-        if parsed_globals.v2_debug:
+        if resolve_v2_debug_mode(parsed_globals):
             parsed_args_to_check = {
                 arg: getattr(parsed_args, arg)
                 for arg in vars(parsed_args) if getattr(parsed_args, arg)
@@ -692,19 +691,18 @@ def _detect_binary_file_migration_change(
                 arg.py_name for arg in arg_table.values()
                 if arg.py_name in parsed_args_to_check
                    and arg.argument_model.type_name == 'blob'
-                   and parsed_args_to_check[arg.py_name].startswith('file://')
             ]
             if arg_values_to_check:
-                uni_print(
-                    'AWS CLI v2 MIGRATION WARNING: When specifying a blob-type '
-                    'parameter starting with `file://`, AWS CLI v2 will assume '
-                    'the content of the file is already base64-encoded. To '
-                    'maintain v1 behavior after upgrading to v2, set the '
-                    '`cli_binary_format` configuration variable to '
-                    '`raw-in-base64-out`. See https://docs.aws.amazon.com/cli/'
-                    'latest/userguide/cliv2-migration-changes.html#'
-                    'cliv2-migration-binaryparam.\n',
-                    out_file=sys.stderr
+                print(
+                    'AWS CLI v2 UPGRADE WARNING: When specifying a blob-type '
+                    'parameter, AWS CLI v2 will assume the parameter value is '
+                    'base64-encoded. To maintain v1 behavior after upgrading '
+                    'to v2, set the `cli_binary_format` configuration '
+                    'variable to `raw-in-base64-out`. See '
+                    'https://docs.aws.amazon.com/cli/latest/userguide'
+                    '/cliv2-migration-changes.html'
+                    '#cliv2-migration-binaryparam.\n',
+                    file=sys.stderr
                 )
 
 
diff --git a/awscli/customizations/cloudformation/deploy.py b/awscli/customizations/cloudformation/deploy.py
index a734453e2e0f..e33b03a8f362 100644
--- a/awscli/customizations/cloudformation/deploy.py
+++ b/awscli/customizations/cloudformation/deploy.py
@@ -25,7 +25,7 @@
 from awscli.customizations.commands import BasicCommand
 from awscli.compat import get_stdout_text_writer
 from awscli.customizations.utils import uni_print
-from awscli.utils import create_nested_client, write_exception
+from awscli.utils import create_nested_client, write_exception, resolve_v2_debug_mode
 
 LOG = logging.getLogger(__name__)
 
@@ -317,12 +317,13 @@ def _run_main(self, parsed_args, parsed_globals):
             s3_uploader = None
 
         deployer = Deployer(cloudformation_client)
+        v2_debug = resolve_v2_debug_mode(parsed_globals)
         return self.deploy(deployer, stack_name, template_str,
                            parameters, parsed_args.capabilities,
                            parsed_args.execute_changeset, parsed_args.role_arn,
                            parsed_args.notification_arns, s3_uploader,
                            tags, parsed_args.fail_on_empty_changeset,
-                           parsed_args.disable_rollback, getattr(parsed_globals, 'v2_debug', False))
+                           parsed_args.disable_rollback, v2_debug)
 
     def deploy(self, deployer, stack_name, template_str,
                parameters, capabilities, execute_changeset, role_arn,
@@ -330,6 +331,18 @@ def deploy(self, deployer, stack_name, template_str,
                fail_on_empty_changeset=True, disable_rollback=False,
                v2_debug=False):
         try:
+            if v2_debug and fail_on_empty_changeset:
+                uni_print(
+                    'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, '
+                    'deploying an AWS CloudFormation Template that '
+                    'results in an empty changeset will NOT result in an '
+                    'error. You can add the -–no-fail-on-empty-changeset '
+                    'flag to migrate to v2 behavior and resolve this '
+                    'warning. See https://docs.aws.amazon.com/cli/latest/'
+                    'userguide/cliv2-migration-changes.html'
+                    '#cliv2-migration-cfn.\n',
+                    out_file=sys.stderr
+                )
             result = deployer.create_and_wait_for_changeset(
                 stack_name=stack_name,
                 cfn_template=template_str,
@@ -342,18 +355,6 @@ def deploy(self, deployer, stack_name, template_str,
             )
         except exceptions.ChangeEmptyError as ex:
             if fail_on_empty_changeset:
-                if v2_debug:
-                    uni_print(
-                        'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, '
-                        'deploying an AWS CloudFormation Template that '
-                        'results in an empty changeset will NOT result in an '
-                        'error. You can add the -–no-fail-on-empty-changeset '
-                        'flag to migrate to v2 behavior and resolve this '
-                        'warning. See https://docs.aws.amazon.com/cli/latest/'
-                        'userguide/cliv2-migration-changes.html'
-                        '#cliv2-migration-cfn.\n',
-                        out_file=sys.stderr
-                    )
                 raise
             write_exception(ex, outfile=get_stdout_text_writer())
             return 0
diff --git a/awscli/customizations/globalargs.py b/awscli/customizations/globalargs.py
index 96b599ce37ea..59582ab61768 100644
--- a/awscli/customizations/globalargs.py
+++ b/awscli/customizations/globalargs.py
@@ -18,9 +18,12 @@
 from botocore.client import Config
 from botocore import UNSIGNED
 from botocore.endpoint import DEFAULT_TIMEOUT
+from botocore.useragent import register_feature_id
 import jmespath
 
 from awscli.compat import urlparse
+from awscli.utils import resolve_v2_debug_mode
+
 
 def register_parse_global_args(cli):
     cli.register('top-level-args-parsed', resolve_types,
@@ -96,7 +99,7 @@ def resolve_cli_connect_timeout(parsed_args, session, **kwargs):
     _resolve_timeout(session, parsed_args, arg_name)
 
 def detect_migration_breakage(parsed_args, remaining_args, session, **kwargs):
-    if not parsed_args.v2_debug:
+    if not resolve_v2_debug_mode(parsed_args):
         return
     url_params = [
         param for param in remaining_args
@@ -104,14 +107,29 @@ def detect_migration_breakage(parsed_args, remaining_args, session, **kwargs):
     ]
     region = parsed_args.region or session.get_config_variable('region')
     s3_config = session.get_config_variable('s3')
+    if (
+            not session.get_scoped_config().get('cli_pager', None)
+            == '' and 'AWS_PAGER' not in os.environ
+    ):
+        uni_print(
+            'AWS CLI v2 UPGRADE WARNING: By default, the AWS CLI version 2 '
+            'returns all output through your operating system’s default pager '
+            'program. To retain AWS CLI v1 behavior after upgrading to AWS '
+            'CLI v2, set the `cli_pager` configuration setting, or the '
+            '`AWS_PAGER` environment variable, to the empty string. See '
+            'https://docs.aws.amazon.com/cli/latest/userguide'
+            '/cliv2-migration-changes.html#cliv2-migration-output-pager.\n',
+            out_file=sys.stderr
+        )
     if 'PYTHONUTF8' in os.environ or 'PYTHONIOENCODING' in os.environ:
         if 'AWS_CLI_FILE_ENCODING' not in os.environ:
             uni_print(
-                'AWS CLI v2 MIGRATION WARNING: The PYTHONUTF8 and '
+                'AWS CLI v2 UPGRADE WARNING: The PYTHONUTF8 and '
                 'PYTHONIOENCODING environment variables are unsupported '
-                'in AWS CLI v2. AWS CLI v2 uses AWS_CLI_FILE_ENCODING '
-                'instead, set this environment variable to resolve this. '
-                'See https://docs.aws.amazon.com/cli/latest/userguide/'
+                'in AWS CLI v2. AWS CLI v2 uses the `AWS_CLI_FILE_ENCODING` '
+                'variable instead; set this environment variable to retain '
+                'AWS CLI v1 behavior after upgrading to AWS CLI v2. See '
+                'https://docs.aws.amazon.com/cli/latest/userguide/'
                 'cliv2-migration-changes.html'
                 '#cliv2-migration-encodingenvvar.\n',
                 out_file=sys.stderr
@@ -129,18 +147,18 @@ def detect_migration_breakage(parsed_args, remaining_args, session, **kwargs):
         )
     if session.get_config_variable('api_versions'):
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: The AWS CLI v2 does not support '
+            'AWS CLI v2 UPGRADE WARNING: The AWS CLI v2 does not support '
             'calling earlier versions of AWS service APIs via the '
             '`api_versions` configuration file setting. To migrate to v2 '
-            'behavior and resolve this warning, remove the `api_versions` '
-            'setting in the configuration file. See '
+            'behavior, remove the `api_versions` configuration setting, and '
+            'test against the latest API versions. See '
             'https://docs.aws.amazon.com/cli/latest/userguide/'
             'cliv2-migration-changes.html#cliv2-migration-api-versions.\n',
             out_file = sys.stderr
         )
     if session.full_config.get('plugins', {}):
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, plugin support '
+            'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, plugin support '
             'is provisional. If you rely on plugins, be sure to lock into '
             'a particular version of the AWS CLI and test the '
             'functionality of your plugins for each upgrade. See '
@@ -151,18 +169,18 @@ def detect_migration_breakage(parsed_args, remaining_args, session, **kwargs):
         )
     if parsed_args.command == 'ecr' and remaining_args[0] == 'get-login':
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: The ecr get-login command has '
-            'been removed in AWS CLI v2. See https://docs.aws.amazon.com/'
-            'cli/latest/userguide/cliv2-migration-changes.html'
-            '#cliv2-migration-ecr-get-login.\n',
+            'AWS CLI v2 UPGRADE WARNING: The `ecr get-login` command has '
+            'been removed in AWS CLI v2. You must use `ecr get-login-password` '
+            'instead. See https://docs.aws.amazon.com/cli/latest/userguide/'
+            'cliv2-migration-changes.html#cliv2-migration-ecr-get-login.\n',
             out_file=sys.stderr
         )
-    if url_params and session.full_config.get('cli_follow_urlparam', True):
+    if url_params and session.get_scoped_config().get('cli_pager', None):
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: For input parameters that have '
+            'AWS CLI v2 UPGRADE WARNING: For input parameters that have '
             'a prefix of http:// or https://, AWS CLI v2 will no longer '
             'automatically request the content of the URL for the '
-            'parameter, and the cli_follow_urlparam option has been '
+            'parameter, and the `cli_follow_urlparam` option has been '
             'removed. See https://docs.aws.amazon.com/cli/latest/'
             'userguide/cliv2-migration-changes.html'
             '#cliv2-migration-paramfile.\n',
@@ -179,27 +197,40 @@ def detect_migration_breakage(parsed_args, remaining_args, session, **kwargs):
                 and f"--{working_param}" in remaining_args
         ):
             uni_print(
-                'AWS CLI v2 MIGRATION WARNING: You have entered command '
+                'AWS CLI v2 UPGRADE WARNING: You have entered command '
                 'arguments that uses at least 1 of 21 hidden aliases that '
-                'were removed in AWS CLI v2. See '
+                'were removed in AWS CLI v2. You must replace usage of the '
+                'obsolete alias with the corresponding working parameter. See '
                 'https://docs.aws.amazon.com/cli/latest/userguide'
                 '/cliv2-migration-changes.html#cliv2-migration-aliases.\n',
                 out_file=sys.stderr
             )
+    # Register against the provide-client-params event to ensure that the
+    # feature ID is registered before any API requests are made. We
+    # cannot register the feature ID in this function because no
+    # botocore context is created at this point.
+    session.register(
+        'provide-client-params.*.*',
+        _register_v2_debug_feature_id
+    )
     session.register('choose-signer.s3.*', warn_if_sigv2)
 
+
+def _register_v2_debug_feature_id(params, model, **kwargs):
+    register_feature_id('CLI_V1_TO_V2_MIGRATION_DEBUG_MODE')
+
 def warn_if_east_configured_global_endpoint(request, operation_name, **kwargs):
     # The regional us-east-1 endpoint is used in certain cases (e.g.
     # FIPS/Dual-Stack is enabled). Rather than duplicating this logic
     # from botocore, we check the endpoint URL directly.
     if 's3.amazonaws.com' in request.url:
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: When you configure AWS CLI v2 '
+            'AWS CLI v2 UPGRADE WARNING: When you configure AWS CLI v2 '
             'to use the `us-east-1` region, it uses the true regional '
-            'endpoint rather than the global endpoint. To continue using '
-            'the global endpoint on v2, configure the region to be '
-            '`aws-global`. See https://docs.aws.amazon.com/cli/latest/'
-            'userguide/cliv2-migration-changes.html'
+            'endpoint rather than the global endpoint. To retain AWS CLI v1 '
+            'behavior after upgrading to AWS CLI v2, configure the `region` '
+            'setting to `aws-global`. See https://docs.aws.amazon.com/cli'
+            '/latest/userguide/cliv2-migration-changes.html'
             '#cliv2-migration-s3-regional-endpoint.\n',
             out_file=sys.stderr
         )
@@ -213,10 +244,10 @@ def warn_if_sigv2(
 ):
     if context.get('auth_type', None) == 'v2':
         uni_print(
-            'AWS CLI v2 MIGRATION WARNING: The AWS CLI v2 only uses Signature '
-            'v4 to authenticate Amazon S3 requests. Run the command `aws '
-            'configure set s3.signature_version s3v4` to migrate to v4 and '
-            'resolve this.\n',
+            'AWS CLI v2 UPGRADE WARNING: The AWS CLI v2 only uses Signature '
+            'v4 to authenticate Amazon S3 requests. To migrate to AWS CLI '
+            'v2 behavior, configure the Signature Version S3 setting to '
+            'version 4.\n',
             out_file=sys.stderr
         )
 
diff --git a/awscli/customizations/paginate.py b/awscli/customizations/paginate.py
index 836b338b0fef..2d64bae611c3 100644
--- a/awscli/customizations/paginate.py
+++ b/awscli/customizations/paginate.py
@@ -33,7 +33,7 @@
 from botocore import model
 
 from awscli.arguments import BaseCLIArgument
-
+from awscli.utils import resolve_v2_debug_mode
 
 logger = logging.getLogger(__name__)
 
@@ -293,7 +293,7 @@ def check_should_enable_pagination_call_parameters(
     naming space and would be missed by the processing above. This function
     gets called on the calling-command event.
     """
-    if parsed_globals.v2_debug:
+    if resolve_v2_debug_mode(parsed_globals):
         cli_input_json_data = session.emit_first_non_none_response(
             f"get-cli-input-json-data",
         )
@@ -304,11 +304,12 @@ def check_should_enable_pagination_call_parameters(
         ]
         if pagination_params_in_input_tokens:
             uni_print(
-                'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, if you specify '
+                'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, if you specify '
                 'pagination parameters by using a file with the '
                 '`--cli-input-json` parameter, automatic pagination will be '
-                'turned off. This is not the case in v1. See '
-                'https://docs.aws.amazon.com/cli/latest/userguide/'
+                'turned off. To retain AWS CLI v1 behavior after upgrading to '
+                'AWS CLI v2, remove all pagination parameters from the input '
+                'JSON. See https://docs.aws.amazon.com/cli/latest/userguide/'
                 'cliv2-migration-changes.html'
                 '#cliv2-migration-skeleton-paging.\n',
                 out_file=sys.stderr
diff --git a/awscli/customizations/s3/subcommands.py b/awscli/customizations/s3/subcommands.py
index 665fa9ae2603..b05ae1857020 100644
--- a/awscli/customizations/s3/subcommands.py
+++ b/awscli/customizations/s3/subcommands.py
@@ -36,7 +36,7 @@
 from awscli.customizations.s3.syncstrategy.base import MissingFileSync, \
     SizeAndLastModifiedSync, NeverSync
 from awscli.customizations.s3 import transferconfig
-
+from awscli.utils import resolve_v2_debug_mode
 
 LOGGER = logging.getLogger(__name__)
 
@@ -1060,7 +1060,7 @@ def run(self):
         if self.parameters['v2_debug']:
             if operation_name == 'copy':
                 uni_print(
-                    'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, object '
+                    'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, object '
                     'properties will be copied from the source in multipart '
                     'copies between S3 buckets. This may result in extra S3 '
                     'API calls being made. Breakage may occur if the principal '
@@ -1464,7 +1464,7 @@ def add_page_size(self, parsed_args):
         self.parameters['page_size'] = getattr(parsed_args, 'page_size', None)
 
     def add_v2_debug(self, parsed_globals):
-        self.parameters['v2_debug'] = parsed_globals.v2_debug
+        self.parameters['v2_debug'] = resolve_v2_debug_mode(parsed_globals)
 
     def _validate_sse_c_args(self):
         self._validate_sse_c_arg()
diff --git a/awscli/customizations/scalarparse.py b/awscli/customizations/scalarparse.py
index a9c56eaa8656..c5217a0db804 100644
--- a/awscli/customizations/scalarparse.py
+++ b/awscli/customizations/scalarparse.py
@@ -33,6 +33,7 @@
 from botocore.exceptions import ProfileNotFound
 
 from awscli.customizations.utils import uni_print
+from awscli.utils import resolve_v2_debug_mode
 
 
 def register_scalar_parser(event_handlers):
@@ -50,10 +51,18 @@ def iso_format(value):
 
 def add_timestamp_parser(session, v2_debug):
     factory = session.get_component('response_parser_factory')
+    print_v2_debug_warnings = v2_debug
     try:
         timestamp_format = session.get_scoped_config().get(
             'cli_timestamp_format',
-            'wire')
+            None)
+        if timestamp_format is not None:
+            # We do not want to print v2 debug warnings if the user explicitly
+            # configured the cli_timestamp_format, they would not be
+            # broken in that case.
+            print_v2_debug_warnings = False
+        else:
+            timestamp_format = 'wire'
     except ProfileNotFound:
         # If a --profile is provided that does not exist, loading
         # a value from get_scoped_config will crash the CLI.
@@ -79,17 +88,19 @@ def identity_with_warning(x):
             if not encountered_timestamp:
                 encountered_timestamp = True
                 uni_print(
-                    'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, all timestamp '
+                    'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, all timestamp '
                     'response values are returned in the ISO 8601 format. To '
-                    'migrate to v2 behavior and resolve this warning, set the '
-                    'configuration variable `cli_timestamp_format` to `iso8601`. '
-                    'See https://docs.aws.amazon.com/cli/latest/userguide/'
-                    'cliv2-migration-changes.html#cliv2-migration-timestamp.\n',
+                    'migrate to v2 behavior, set the configuration variable '
+                    '`cli_timestamp_format` to `iso8601`. See https://'
+                    'docs.aws.amazon.com/cli/latest/userguide/'
+                    'cliv2-migration-changes.html'
+                    '#cliv2-migration-timestamp.\n',
                     out_file=sys.stderr
                 )
             return identity(x)
 
-        timestamp_parser = identity_with_warning if v2_debug else identity
+        timestamp_parser = identity_with_warning \
+            if print_v2_debug_warnings else identity
     elif timestamp_format == 'iso8601':
         timestamp_parser = iso_format
     else:
@@ -101,4 +112,4 @@ def identity_with_warning(x):
 def add_scalar_parsers(session, parsed_args, **kwargs):
     factory = session.get_component('response_parser_factory')
     factory.set_parser_defaults(blob_parser=identity)
-    add_timestamp_parser(session, parsed_args.v2_debug)
+    add_timestamp_parser(session, resolve_v2_debug_mode(parsed_args))
diff --git a/awscli/data/cli.json b/awscli/data/cli.json
index 25687399d05c..d75489e88664 100644
--- a/awscli/data/cli.json
+++ b/awscli/data/cli.json
@@ -69,6 +69,11 @@
             "action": "store_true",
             "dest": "v2_debug",
             "help": "<p>Enable AWS CLI v2 migration assistance. Prints warnings if the command would face a breaking change after swapping AWS CLI v1 for AWS CLI v2 in the current environment. Prints one warning for each breaking change detected.</p>"
+        },
+        "no-v2-debug": {
+            "action": "store_true",
+            "dest": "no_v2_debug",
+            "help": "<p>Disable AWS CLI v2 migration assistance.</p>"
         }
     }
 }
diff --git a/awscli/examples/global_options.rst b/awscli/examples/global_options.rst
index d450cf0ce78a..914d070ed329 100644
--- a/awscli/examples/global_options.rst
+++ b/awscli/examples/global_options.rst
@@ -74,3 +74,7 @@
   
   Enable AWS CLI v2 migration assistance. Prints warnings if the command would face a breaking change after swapping AWS CLI v1 for AWS CLI v2 in the current environment. Prints one warning for each breaking change detected.
   
+``--no-v2-debug`` (boolean)
+  
+  Disable AWS CLI v2 migration assistance.
+  
diff --git a/awscli/examples/global_synopsis.rst b/awscli/examples/global_synopsis.rst
index 12865958a809..1d8295f550ed 100644
--- a/awscli/examples/global_synopsis.rst
+++ b/awscli/examples/global_synopsis.rst
@@ -13,3 +13,4 @@
 [--cli-read-timeout <value>]
 [--cli-connect-timeout <value>]
 [--v2-debug]
+[--no-v2-debug]
diff --git a/awscli/utils.py b/awscli/utils.py
index 3e7e9d6e8e37..4e4809a5f166 100644
--- a/awscli/utils.py
+++ b/awscli/utils.py
@@ -134,6 +134,18 @@ def find_service_and_method_in_event_name(event_name):
     return service_name, operation_name
 
 
+def resolve_v2_debug_mode(args):
+    # Resolve whether v2-debug mode is enabled,
+    # following the correct precedence order.
+    if no_v2_debug := getattr(args, 'no_v2_debug', False):
+        return False
+    if getattr(args, 'v2_debug', False):
+        return True
+    if os.environ.get('AWS_CLI_UPGRADE_DEBUG_MODE', '').lower() == 'true':
+        return True
+    return False
+
+
 def is_document_type(shape):
     """Check if shape is a document type"""
     return getattr(shape, 'is_document_type', False)
diff --git a/tests/functional/test_api_versions.py b/tests/functional/test_api_versions.py
index 2c3d339ab1ba..e98f0159cb44 100644
--- a/tests/functional/test_api_versions.py
+++ b/tests/functional/test_api_versions.py
@@ -59,7 +59,7 @@ def test_v2_debug_migration_warning(self):
         # Make sure that the migration warning is printed since the user
         # specified --v2-debug
         self.assertIn(
-            'AWS CLI v2 MIGRATION WARNING: The AWS CLI v2 does not support '
+            'AWS CLI v2 UPGRADE WARNING: The AWS CLI v2 does not support '
             'calling earlier versions of AWS service APIs via the '
             '`api_versions` configuration file setting.',
             stderr
diff --git a/tests/unit/customizations/s3/test_subcommands.py b/tests/unit/customizations/s3/test_subcommands.py
index c0b5af9eb804..b19d65a352ed 100644
--- a/tests/unit/customizations/s3/test_subcommands.py
+++ b/tests/unit/customizations/s3/test_subcommands.py
@@ -635,7 +635,7 @@ def test_v2_debug_mv(self):
         cmd_arc.create_instructions()
         self.patch_make_request()
         cmd_arc.run()
-        warning_str = 'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, object '\
+        warning_str = 'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, object '\
                       'properties will be copied from the source in multipart '\
                       'copies between S3 buckets.'
         output_str = f"(dryrun) move: {s3_file} to {s3_file}"
diff --git a/tests/unit/customizations/test_globalargs.py b/tests/unit/customizations/test_globalargs.py
index f3bf17b4a680..4ff130b9d1f7 100644
--- a/tests/unit/customizations/test_globalargs.py
+++ b/tests/unit/customizations/test_globalargs.py
@@ -10,6 +10,8 @@
 # distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
 # ANY KIND, either express or implied. See the License for the specific
 # language governing permissions and limitations under the License.
+from unittest.mock import patch
+
 from botocore.session import get_session
 from botocore import UNSIGNED
 import os
@@ -186,6 +188,63 @@ def test_cli_connect_timeout_for_blocking(self):
         self.assertEqual(
             session.get_default_client_config().connect_timeout, None)
 
+    def test_register_feature_id(self):
+        parsed_args = FakeParsedArgs(v2_debug=True)
+        session = get_session()
+        globalargs.detect_migration_breakage(
+            parsed_args,
+            [],
+            session
+        )
+        # Verify the correct feature ID is registered during the
+        # provide-client-params event.
+        with (mock.patch('awscli.customizations.globalargs.register_feature_id')
+              as mock_register_feature_id):
+            session.emit(
+                'provide-client-params.s3.ListBuckets',
+                params={},
+                model={},
+            )
+        mock_register_feature_id.assert_any_call(
+            'CLI_V1_TO_V2_MIGRATION_DEBUG_MODE'
+        )
+
+    def test_ecr_login_v2_debug(self):
+        parsed_args = FakeParsedArgs(command='ecr', v2_debug=True)
+        remaining_args = ['get-login']
+        session = get_session()
+        with capture_output() as output:
+            globalargs.detect_migration_breakage(
+                parsed_args,
+                remaining_args,
+                session
+            )
+        # Verify the expected warning is printed
+        self.assertIn(
+            'AWS CLI v2 UPGRADE WARNING: The `ecr get-login` command has '
+            'been removed in AWS CLI v2.',
+            output.stderr.getvalue()
+        )
+
+    def test_ecr_login_v2_debug_env_var(self):
+        parsed_args = FakeParsedArgs(command='ecr')
+        remaining_args = ['get-login']
+        session = get_session()
+        env = {'AWS_CLI_UPGRADE_DEBUG_MODE': 'true'}
+        with capture_output() as output:
+            with mock.patch('os.environ', env):
+                globalargs.detect_migration_breakage(
+                    parsed_args,
+                    remaining_args,
+                    session
+                )
+        # Verify the expected warning is printed
+        self.assertIn(
+            'AWS CLI v2 UPGRADE WARNING: The `ecr get-login` command has '
+            'been removed in AWS CLI v2.',
+            output.stderr.getvalue()
+        )
+
     def test_v2_debug_python_utf8_env_var(self):
         parsed_args = FakeParsedArgs(v2_debug=True)
         session = get_session()
@@ -194,7 +253,7 @@ def test_v2_debug_python_utf8_env_var(self):
             with capture_output() as output:
                 globalargs.detect_migration_breakage(parsed_args, [], session)
                 self.assertIn(
-                    'AWS CLI v2 MIGRATION WARNING: The PYTHONUTF8 and '
+                    'AWS CLI v2 UPGRADE WARNING: The PYTHONUTF8 and '
                     'PYTHONIOENCODING environment variables are unsupported '
                     'in AWS CLI v2.',
                     output.stderr.getvalue()
@@ -208,7 +267,7 @@ def test_v2_debug_python_utf8_resolved_env_var(self):
             with capture_output() as output:
                 globalargs.detect_migration_breakage(parsed_args, [], session)
                 self.assertNotIn(
-                    'AWS CLI v2 MIGRATION WARNING: The PYTHONUTF8 and '
+                    'AWS CLI v2 UPGRADE WARNING: The PYTHONUTF8 and '
                     'PYTHONIOENCODING environment variables are unsupported '
                     'in AWS CLI v2.',
                     output.stderr.getvalue()
@@ -222,7 +281,7 @@ def test_v2_debug_python_io_encoding_env_var(self):
             with capture_output() as output:
                 globalargs.detect_migration_breakage(parsed_args, [], session)
                 self.assertIn(
-                    'AWS CLI v2 MIGRATION WARNING: The PYTHONUTF8 and '
+                    'AWS CLI v2 UPGRADE WARNING: The PYTHONUTF8 and '
                     'PYTHONIOENCODING environment variables are unsupported '
                     'in AWS CLI v2.',
                     output.stderr.getvalue()
@@ -241,7 +300,7 @@ def test_v2_debug_s3_sigv2(self):
                 context={'auth_type': 'v2'},
             )
         self.assertIn(
-            'AWS CLI v2 MIGRATION WARNING: The AWS CLI v2 only uses Signature '
+            'AWS CLI v2 UPGRADE WARNING: The AWS CLI v2 only uses Signature '
             'v4 to authenticate Amazon S3 requests.',
             output.stderr.getvalue()
         )
diff --git a/tests/unit/customizations/test_paginate.py b/tests/unit/customizations/test_paginate.py
index 03eed8e45f30..2b0a1ed818d4 100644
--- a/tests/unit/customizations/test_paginate.py
+++ b/tests/unit/customizations/test_paginate.py
@@ -335,6 +335,7 @@ def test_v2_debug_call_parameters(self):
         # migration warning should be printed.
         # From setUp(), the limit_key is 'Bar'
         input_tokens = ['Foo', 'Bar']
+        self.parsed_globals.no_v2_debug = False
         self.parsed_globals.v2_debug = True
         self.parsed_globals.paginate = True
         self.session.emit_first_non_none_response.side_effect = partial(
@@ -355,7 +356,7 @@ def test_v2_debug_call_parameters(self):
             # We should have printed the migration warning
             # because the user specified {Bar: 10} in the input JSON
             self.assertIn(
-                'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, if you specify '
+                'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, if you specify '
                 'pagination parameters by using a file with the '
                 '`--cli-input-json` parameter, automatic pagination will be '
                 'turned off.',
@@ -387,7 +388,7 @@ def test_v2_debug_call_params_does_not_print_for_cmd_args(self):
             # We should not have printed the warning because
             # the user did not specify any params through CLI input JSON
             self.assertNotIn(
-                'AWS CLI v2 MIGRATION WARNING: In AWS CLI v2, if you specify '
+                'AWS CLI v2 UPGRADE WARNING: In AWS CLI v2, if you specify '
                 'pagination parameters by using a file with the '
                 '`--cli-input-json` parameter, automatic pagination will be '
                 'turned off.',
diff --git a/tests/unit/test_clidriver.py b/tests/unit/test_clidriver.py
index a88e13ed76ed..bfc17cf71ab8 100644
--- a/tests/unit/test_clidriver.py
+++ b/tests/unit/test_clidriver.py
@@ -92,11 +92,6 @@
                 "type": "int",
                 "help": ""
             },
-            "migrate-v2": {
-                "action": "store_true",
-                "dest": "migrate_v2",
-                "help": "",
-            }
         }
     },
 }
diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index 8030e2eba786..3f979d8fd25d 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -23,7 +23,7 @@
     split_on_commas, ignore_ctrl_c, find_service_and_method_in_event_name,
     is_document_type, is_document_type_container, is_streaming_blob_type,
     is_tagged_union_type, operation_uses_document_types, ShapeWalker,
-    ShapeRecordingVisitor, OutputStreamFactory
+    ShapeRecordingVisitor, OutputStreamFactory, resolve_v2_debug_mode
 )
 
 
@@ -135,6 +135,32 @@ def test_returns_none_if_event_is_too_short(self):
         self.assertIs(operation, None)
 
 
+class TestV2DebugResolution(unittest.TestCase):
+    def test_no_v2_debug_flag_takes_precedence(self):
+        args = mock.Mock(no_v2_debug=True, v2_debug=True)
+        with mock.patch.dict(os.environ, {'AWS_CLI_UPGRADE_DEBUG_MODE': 'true'}):
+            self.assertFalse(resolve_v2_debug_mode(args))
+
+    def test_v2_debug_flag_enabled(self):
+        args = mock.Mock(no_v2_debug=False, v2_debug=True)
+        self.assertTrue(resolve_v2_debug_mode(args))
+
+    def test_env_var_enabled(self):
+        args = mock.Mock(no_v2_debug=False, v2_debug=False)
+        with mock.patch.dict(os.environ, {'AWS_CLI_UPGRADE_DEBUG_MODE': 'true'}):
+            self.assertTrue(resolve_v2_debug_mode(args))
+
+    def test_all_disabled(self):
+        args = mock.Mock(no_v2_debug=False, v2_debug=False)
+        with mock.patch.dict(os.environ, {}, clear=True):
+            self.assertFalse(resolve_v2_debug_mode(args))
+
+    def test_env_var_non_true_value(self):
+        args = mock.Mock(no_v2_debug=False, v2_debug=False)
+        with mock.patch.dict(os.environ, {'AWS_CLI_UPGRADE_DEBUG_MODE': 'false'}):
+            self.assertFalse(resolve_v2_debug_mode(args))
+
+
 class MockProcess(object):
     @property
     def stdin(self):