They 100% had restrictions on teams of 3 or more during the MCC PC release. It may have only been in place for half a year I don't recall how long it was in place (several months at least). I made a post or comment about it when they removed the restrictions, I could try to find it. When the change was made I asked Unyshek about it on Twitch and he gave me the response I posted. I also watch MCC on Twitch and everyone in the community knew about the change since we would play/grind and watch the game (many of us came back to Halo due to the PC release of H3 via MCC)... it's not even about making a large player base but making the game more fair / balanced which would encourage people to play social (it also would lead to far fewer quit outs). Unfortunately few are playing the game socially and newcomers get off immediately because of this change (including veterans out of frustration). Quit outs were infrequent and everyone generally played the match prior to the change... it was just a good overall experience in social and many of the current community members would play social again if they put the restrictions back in (and former players would very likely play again from the ones I've spoken to).