No, Dolby Atmos beyond 5.1 is not supported on Apple Music for macOS Monterey 12.2.
I just called Apple support, and they answered that Apple Music on macOS Monterey currently only supports 5.1. They also pointed to this Discussions article which has an answer from a community specialist:
https://discussions.apple.com/thread/253694386
The support rep also asked to provide feedback on this missing feature here, in order to prioritise the feature: https://www.apple.com/feedback/
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