In higher ELO, people would target good players with "avoid player"^1, effectively soft-banning those people from match making because the pool was small enough. They would still get put in matches eventually but their queues would blow out a lot.
From memory it did not have an explicit "match me with this person" button, but you could thumbs up players in the post-match podium as well as endorse them which may have soft-factored into matching you with them again.
\1 I think it was called this. It was a general "bad attitude" marker, not a "bad team mate" or "bad opponent" marker.