We are fellow users and have no more idea than you when Apple and Nikon will figure this out and provide support. It starts with
You will need to use alternative means to see these Z9 RAW images as it is simply not supported in macOS 12.4 at this time.
Nikon, and then Apple must implement the camera RAW code, test it, and then determine when it can be rolled out in an operating system update/upgrade. Unless Apple provides this support in the forthcoming macOS 12.5, it may only be available in Ventura when it is released. Apple does not make retroactive camera RAW support to prior operating systems.
See the living document: Digital camera RAW formats supported by iOS 15, iPadOS 15, and macOS Monterey - Apple Support
A current Z9 RAW image opens nicely in Affinity Photo v1.10.5 because that vendor has its own camera RAW support internal to the application.