Khakiconsidering blizzard ripped off many aspects of tf2's gameplay, I don't see why valve can't just rip off Overwatch's competitive matchmaking system
they dont even have to look at other companies, just get the ideas from csgo, a game with actual decent ELO
unless the guy in charge of CSGO MM left the company this should be piss easy, the only problem i see is calculating ELO for medics. they could probably make it half dependant on raw heals per minute, half on average player performance
edit: also if they do implement class limits, their system for it is flawed and can be exploited to have more players than the supposedly allowed as can be seen in faceit sometimes. they should look at the community plugin for classlimits and fix their own version. a improved demo recording system would be nice too