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?
They'd still be usable by devs. We'd get VS code on the App Store and some kind of iOS-style ability to run unsigned binaries on some limited number of computers with an Apple Developer subscription.
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?