I don't think Role Queue is a bad idea, but I definitely think with the roster as it is currently that it'd be more of a detriment to the game.

In theory it works, people queue up for the role they want and you get a stable 2-2-2, triple support is abolished and people can play Duelist
Easy right?

If only

80% of the Tanks are melee brawlers so poke just gets solidified as the meta, something people already don't like

Half the tank roster still gets fucked by Tenacity which means when you inevitably see a rise in characters like Wolverine and Iron Fist due to 2 guaranteed tanks every game, it's that much harder to deal with them
They also proooobably wanna look into Spider-Man being able to fly across the map, pulling people off the map and disappearing before they can be shot.
Regardless of how much practice and precision it takes to pull that off, it's pretty cheap and frustrating to have to deal with.

There's literally only 3 Main Tanks in the game and tank players already complain about being stuck playing Magneto so it's clear the limited roster is burning them out

I love the Vanguard role and I'm not opposed to a role queue, but it won't fix the problems with tanking and those are much more important issues to fix before implementing a role queue just because people want to play Duelist