With the Installation of Cubase 12 I can no longer find EZ Drummer nor any EZ Keys. They are even not listed in the Plugin Managers Blocklist
Then you must be using an M1 Mac in native mode. I’m surprised you haven’t read about this already? You can still use them if you run under Rosetta.
Mac in native mode does not support version 2 vst instruments which toontrack are.
If not then you should be able to see them still and maybe you need to scan again or direct to the correct location.
Ez Bass is VST3 now and works in cubase in native mode, I don’t have Ez Drummer or Ez Keys but Superior Drummer 3 works great when cubase is running in Rosseta mode.
I have to use superior drummer 3 and some other plugins that are not m1 compatible yet so I run cubase in rosetta mode and to be honest the performance is great!!
Re-check your plugins directory and re-scan them if necessary.
I have EZBass, EZDrummer and Superior Drummer 3 and all are working fine.