No one knows that. Maybe 2024? I bought the Reason 12 upgrade 9 month ago based on the promise that they are working on M1 support. Didn't think it would take so long.

Whenever there is an Apple M1 Native version of Reason I will upgrade immediately.
I don't care about the Reason DAW, just want to use Reason VST native in Ableton (like all my other Plugins, except Native Instruments...)