Would it be possible to integrate the YTM Desktop playback controls within vscode? Maybe with an extension for vs code that does this integration.
It's possible via Companion Server API.
Could this be in the planning of the application at some point?
Yes, will be available in the next release and will be accessed by http://localhost:9863/query

Any date when it will be available?
we have the date in mind first of June
Api available and doc is here - https://github.com/ytmdesktop/ytmdesktop/wiki/Remote-Control-API