Twice tonight I got insta-rematched against the team I had played in the previous match. I thought the system was supposed to prevent this kind of thing? It's really annoying when you lose a match against a cheater and then have to play against the exact same 4 man team the next game.
It depends upon if there is a large enough pool at that given moment to match you with other people. If there isn't, then you'll play the same team again.