Just to be clear, PPC-Intel fat/universal binaries are still supported even on Big Sur, the PPC portion is just ignored. I don't expect Intel-Arm binaries to go away any time soon.
I believe what you're really thinking of is Rosetta though. That, indeed, is sadly unlikely to be around forever. We have history as an indication of that.
I believe what you're really thinking of is Rosetta though. That, indeed, is sadly unlikely to be around forever. We have history as an indication of that.