Since OWL and Ranked are meant to have same ruleset, if it goes live it goes for both (eventually in a short timeframe), but to be fair I don't really see it changing much for ranked. Unless they have huge changes coming for some heroes to make them viable in 2-2-2 I really don't see this making any sense.
Game still won't be fun, if a thrower/troll enters into your game (specifically for your team). Problem is mostly the people not the game though, what would change people and their attitude is different story though..,
I am not really positive about how it will work in the end. If looking at fun experience. Like how many of those Roadhog 1-tricks can actually play Dva or Zarya? If they switch a tank they probably pick Main Tank instead. Just like those games I have played at plat, when my healers won't even heal me as Rein, when I am just chilling at payload with 200hp and waiting for Ana to shoot me a little bit. but she walks past me...
One thing I do like with possible RoleQueue is each rank having it's own rating, but are you really 4k DPS, if you 1-trick Symmetra or Torbjörn? (or any hero really).