Being a long term mountain biker, I was already pretty sold on disc brakes. So for me it was an easy choice when I went back to road bikes and I was actually quite pleased to see disc brakes on the menu. Roadie friends who have only recently discovered disc brakes really like them too. I don't know anyone who has used discs planning to go back to rim brakes, but I'm sure there will be an exception here on BF though, lol. It seems to me that most people kicking against disc brakes haven't even used them. All sorts of talk of problems and additional maintenance that is massively exaggerated.
Back to the question of manufacturers going back to rim brakes? IMHO not a chance except in very niche circumstances. A better question might be how long will high-end group sets even include rim brake options?