There have been changes to the way that macOS 12 checks executable code when asked to run it. Summarised in a diagram.
How macOS checks executable code before it’s loaded and run, in macOS 10.15 and 11.0. Covering integrity checks using hashes, and validity of the signing certificate, on Intel and ARM.
Although most were worried about Apple’s failure to deliver upgrades to Big Sur, the most serious problem left many users unable to launch any apps.
Apple provides detailed information about how to stunt your Mac’s performance to mitigate against MDS, but doesn’t mention how notarization has become mandatory, and can block extensions and apps from running.
Apple Mobile File Integrity is a combination of a KEXT and a LaunchDaemon which check app signatures, entitlements, and provisioning profiles.