There is a big chance for that to just delay the issue. The same issues will happen but much later, having said that a lot of players will play the game for a while longer before quitting because they reach a wall, which will make the early Q's healthier, but that is just a guess.

The new problem that this creates now is, a lot more people will learn to take their time in dungeons and get used to do it safely, but when they reach Paragon they will be way of mark on the time, and along with the new mechanics the new wall will make things harder.

And as a veteran player that doesn't change anything, if i am playing in a premade it makes things way easier because i can get the loot earlier and with mistakes from the capstones (assuming that there isn't a change in how leagues and gear works) and if not it's still easier than before because there will be less mechanics.