PoisnCopy is now on 100 servers which is the capacity based on this post from Discord. I hope to verify this bot at some point, but it might be take a while.
Therefore, I created PoisnCopy2. Odds are the bot will be offline. If you need the bot turned on, then please feel free to donate and I can turn it on. If you cannot get the project to work then you can try creating an issue in GitHub.
Discord channel copy bot
Add the bot to BOTH of your servers using this link. (NOTE: You must be the OWNER (Not just an admin) of BOTH servers) https://discord.com/oauth2/authorize?client_id=1114582921827864687&scope=bot&permissions=396211112976
DISCLAIMER: There is no guarantee that I will keep this bot running on the server at any given point, use at your own risk
Use: /copychannel
The bot will list the channels in the server that you are typing in. You must enter the ID of the channel that you want to copy and then I will give you a command to copy and paste in the new server.
Make sure your bot can see which channel you are typing in (check left hand side)
*Note: The /copychannel command is just to list the IDs, once you have them, you can just use the /loadchannelcommand.
i.e.
-> /copychannel
-> "Here is your list of channels:
123456752146761758-general
--Thats all of the channels!--
Copy command: /loadchannel server_id:123456737220528146 channel_id:###
Export command: /exportchannel server_id:123456737220528146 channel_id:###"
-> /loadchannel server_id: 123456737220528146 channel_id: 123456752146761758 new_channel_name: testing Paste this in the Server that you want to put copy the channel into
-> Channel Name It will create a new channel in the server that you are in 
-> "Starting copy...
-> Collecting messages...
-> Organizing messages...
-> Creating channel...
-> Posting 218 messages... (this could take awhile)
-> new-chan copy complete!" It will tell you when it is done, copying hundreds/thousands of messages can take a LONG time, be patient
-> /exportchannel server_id: 768249837220528146 channel_id: 768562880751730718 This will compile all of your message into a CSV File
Contributions are welcome! Just create a PR and I will review it.
In order to run the project on your own, you will need to rename the test-config.json file to config.json and then you need to fill in the corresponding fields from your https://discord.com/developers/applications specific application. I will not go into specifics on creating your own discord bot here.