I get these from every vendor/manufacturer every time Apple does an update. They just don't get to tests the final release of the OS until it is released, so they can't be assured it all still works right. They have to send these CYA emails.
I can absolutely attest to that. We've had one of the new ARM Mac Mini's in office for a while with the pre-release macOS Big Sur, and we made sure things were happy on that, only to find on Big Sur public release day that the final OS caused issues with BIAB. So there's one reason to go with the Windows version - a few less surprises than the Mac version!