I don't want dynamic queue to die.
But it probably will : ( And by that I mean not many will care about it/respect its ranking system.
This is because it's too hard for most players to find groups to play with who are similar enough skill/mindset/schedule. I've probably put 40+ hours in to just trying to FIND consistent players (talking to them, doing tryout games, organizing times we can play with others). Sure, I've made some progress by putting in this much time outside of ranked games to make future games more enjoyable, but it's wayy too much time/effort. I doubt many are crazy enough to go through the work to do so.
What happens when people can't play the mode as seriously as they might want to? They'll end up treating it as a joke and enter it only for funzies.
Also, solo queue is coming back soon. You know, that mode that you can jump in to ANY time you want without having to wait on 4 others. Man, I hate that mode, dynamic is where it's at, but it's too inaccessible.