There is no confirmation on any in-game features to introduce a role queue or a 2-2-2 team composition ruleset for any Overwatch game mode yet. The last news we had on this was with recent interviews with Game Director Jeff Kaplan that they are looking into the possibility and that the development team was working on rebuilding the matchmaker to adapt to the obstacles role queue would present.
I myself personally wish there was follow up news on this, and hopefully changes to Competitive regardless of what they are, do come soon.