I’m just a messenger, so don’t take this as me endorsing, however…
Apple can already completely block certain Mac apps from opening without notarization, just like they can on iOS.
In fact, there once was a bug that stopped all Mac apps from opening, see here…
If you are seeing long delays in launching apps or being unable to open Mac Apps at all, this may be due to Apple having significant problems right...
www.macrumors.com
As long as you are connected to the Internet, Apple can absolutely stop any Mac app they want from opening.