Matchmaking fix idea.
So rather than lock people out of their favored character through either hero vetos or allowing only unique heroes in a match, how about we try it another way.
Instead have the match look for queues based on combat role. You select your hero as you queue up then get put in matches that has a slot open for that role. each team will fill up based on what is still required and teams should consist of a vanguard, heavy, assassin and hybrid.
I feel this might help go a long way to alleviating the problems we face without having to force players into roles they'd rather not be in.
I didn't find the right solution from the internet.