Apple is its own thing. It is not fully inconceivable that the feds (and therefore everyone else) would switch to MacOS if Windows became [even more] unsupportable, but I doubt Microsoft can provide Office at even the sad level it achieves on Windows and it would take Apple time to ramp up supply.
Linux is an easy sell unless people are hooked on some application or game that doesn't run on it, then it's hard. The interface is familiar enough now (especially with KDE, but there are some other basically credible options) that they won't have a lot of room to complain so long as they don't have problems. That part is going to depend on the hardware, and IME they will have the fewest problems with AMD CPU and GPU now. If they have Intel it might or might not be OK; if they've got Nvidia they're likely to have a bad time at least sometimes.
Business is increasingly using web-based tools for everything, which is not itselft a bad thing- if only more of them were self-hosted. But either way, this decreases the dependence on Windows. I've worked where there's a few Windows machines for clerical staff, or where there's a Mac for the graphics department. That can be Windows' fate again.