Photomator relies largely on macOS for RAW processing, so I wouldn’t expect it to remain permanently tied to RAW Engine 8.
That said, I haven’t seen any information from Apple confirming exactly when or how Photomator will make use of the RAW-related changes in macOS 27. At present, Apple simply states that Photomator supports the RAW formats available through macOS RAW support.
So, where Photomator relies on Apple’s system-level RAW processing, I would expect macOS 27 to bring the newer RAW support to the app as well. However, we’ll probably have to wait for the final releases of macOS 27 and Photomator to know exactly how this will be implemented.
Just a friendly note: This is the German-language Apple Support Community. Posting your question in German will make it easier for more community members to understand it and offer assistance.