A re-queue would really help the game community
I like the add friend at the end of games, that said adding an option to re-queue the whole team would be a great addition to play and the community (you know summoner code Make Friends). Some teams just hit it off, but players are always In hurry to get back to queue. Even if the whole team friends often people have move into new game queues immediately after, so recreating that great experience is difficult at best. Also with pre made it would easily facilitate another game rather than needing to recreate another and hope people didn't just instant queue again.
I also think that it would have a side effect of reducing toxic issues. You have a great game you queue again and maybe the game doesn't go great you know they are there doing the best they can and just having a bad match or playing a stronger team.