That's the only thing stoping Apple? Not the fact that if they did that every mac out there would become unusable?
I don’t believe they changed anything about app installation in relation to their arm processors.
Why? Their whole "Pro" line is targeting developers. How many enterprises/startups would have to switch away from macs if they cannot be used by their devs any more?
As for why Apple doesn't care about devs, I don't know, but they are not afraid of massive, breaking changes. Remember a few years ago when they permanently deleted the entire MacOS game back catalog by removing 32-bit support?
Is there still a sizable number of people using Macs for other work (like school or design) like in the old days?