While I'm sure the more casual players I play with would switch systems if I and other "alpha gamers" in the groups really pushed for it, I don't want to make people buy new books just so we can struggle through a new system where the DM lacks system mastery. But I also am no longer boostering for WotC products.
So I think what is actually going to happen for the more casual 5e gamers in this sort of situation is that, whereas before they were encouraged by their groups to not just own the PHB but also get Xanathar's or Tasha's to really have more options, now the leading voices at the table in terms of purchasing are going to, on average, be much more oriented towards "oh you don't need to buy that, here, just borrow mine". And generally the mood is going to be much less "this is our game for the long haul" and much more "this is our game for now", and, where the rub comes for WotC, when 5.5 comes out there will be nobody pressuring the more casual players to buy it, and groups that would have otherwise bought PHBs and "given it a try" will give it a pass. The dedicated 5e groups will just keep on 5eing with the stuff they already own until their resident alpha gamers fall in love with one of the 5e semi-clones that will inevitably arise in the coming years.
At least that's how I see it going for the book based groups. I don't really understand people's relationships with D&D Beyond well enough to begin to theorize about the dynamics of how the groups and casual players plugged into that service will adapt to WotC's heel-turn. In any case I think it is now much more the future of D&D than it was before, because I think WotC has just absolutely neutered their book-selling business.