I think it’s possible in this day and age. It just won’t be a game like Vanilla. I’d imagine it’d be more like Classic, except progressive. But the relative quickness in which people clear content will be like Classic not Vanilla. So really, it’ll be a bit like LFR. Everyone will be geared equally. There will be no differentiation between players.
Vanilla was very time consuming. Very discriminating in terms of who got the gear and who didn’t. Not gonna fly today.