I dare say that since it's related to Android Studio 4.2 then when that version is ready compose will be ready too

I hate to burst this bubble but the first dev release of compose was related to Studio 4.0, and moved to 4.1 and now 4.2 as Studio releases have continued 🙂

I think it much more dependant on new Kotlin backend becoming stable :)

Yes, as @Adam Powell said, I think it has more to do with Canary builds, not a specific version.

Right, anything not ready to graduate to stable yet in an Android Studio release moves to the next canary and is removed from the beta track for that version