I'm not 100% sure on how this works, but I believe the Unicode support is going to be tied to the version of Android itself. As far as can tell, Android 12 supports Unicode 13? Android 12L (an update adding better support for tablets and foldable devices) added Unicode 14 support.
Based on what I've been able to find out, the emoji font can now be updated separately from Android itself as of Android 12. I'm not sure, though, if Google pushes out the updates directly or if that's still reliant upon the phone manufacturer to update.