Syntax highlighting stopped working in .heex files with VSCode 1.73.1

[Ninigi]

No problems until I updated VSCode

Version: 1.73.1
Commit: 6261075646f055b99068d3688932416f2346dd3b
Date: 2022-11-09T03:54:53.913Z
Electron: 19.0.17
Chromium: 102.0.5005.167
Node.js: 16.14.2
V8: 10.2.154.15-electron.0
OS: Linux x64 6.0.6-76060006-generic
Sandboxed: No

I added the emmet setting from the README

"emmet.includeLanguages": {
    "phoenix-heex": "html"
}

but still didn't work.

After some googling I found this post, added

 "files.associations": {
    "*.heex": "phoenix-heex"
}

now it works again.

Is this something that should have been automatically resolved, did I screw up something (I really don't have many custom settings or extensions), or should it be added to the README instructions?