☒ I think so. There would be code changes to bring it up to a more modern hotwire/stimulus syntax, but overall it would be be the same.

I'm not sure why it explicitly requires the .css, but it could have something to do with the extension not being scss, so it wasn't found by default.

That does appear to be the case, but it could be included in the libraries elsewhere in a Rails 7 app. I haven’t looked too deeply where Rails 7 or which library would pull those in. It could be Hotwire related as far as the way we should approach channels and broadcasts.

Personally, seeing ActionCable moving into a "background" resource that is consumed via Hotwire is a good thing. But for existing applications, we may still need to import in the custom channels that we used in the past which means that we would need to keep the @rails/actioncable library.

The edge guides still show importing this in on custom channels. https://edgeguides.rubyonrails.org/action_cable_overview.html#client-side-components 

I didn't make any changes with Rails UJS. I wonder if there is anything else going on that could affect it. Are you able to confirm that the asset builds are being created?

 I would likely use their new download option to have the assets pulled down instead of referencing the CDN.