Done so, the new topic for that specific issue is: Default AU from Projucer fails auval on Apple Silicon Big Sur (DTK) [SOLVED]
I’d be interested if @zabukowski (or whoever is happily validating AUs on their ARM64 macs) could comment there with the version number of auval that they have (and possibly of macOS, I guess that might be a factor too)
EDIT: I’ve solved the issue, visit the linked topic for the detailed description of what the problem was