I'm not a fan of the new dialogue screens. The old ones loaded quickly enough for me.
So it should not affect partiesMatchmaker currently doesn't balance teams after finding enough people to start a game. This was fine in theory since a ranked system would make it so all the players in a match would be close in skill. But ranked isn't introduced since then and we decided to have a temporary solution to imbalances.
Balancing done based on previous games and parties won't be split.