And now it seems that a mere two channels is the limit from Apple Music, at least under the latest version of Monterey (12.3.1)! In other words, no surround support at all! The TV app is still limited to 5.1. Apple, come on, this is ridiculous!

Yeah, this is crucial. It's nice to hear that Monterey can configure speaker setups with more than 8 channels (which is the limit under Big Sur), but they need to be recognized in other apps.