Yes, Cubase 12 will support Apple silicon natively, for VST3.
VST2 will only be able to run in Rosetta 2 mode though.
Cubase 12 will introduce native Apple silicon support to begin with. Please be aware that VST 2 is not supported on native Apple silicon, except when run in Rosetta 2 mode. So please make sure that you let the plug-in manufacturers still hesitating to release VST 3 versions know that it’s about time!