A new version of Ableton is now available, it supports M1 processors natively. It will run by default M1 natively. When used on an Apple Silicon computer, the Universal build of Live 11.1 only recognizes VST2 and VST3 plug-ins natively compiled for Apple Silicon. Our plug-ins are not yet natively supported so they will not show up, you need to run Ableton in Rosetta mode. You can check Ableton's article about it: Plug-ins on Mac in Live 11.1
AU plug-ins will work, they automatically run in compatibility mode.