I think that's backwards. The Mets stop on the 7 has two platforms, both much wider than that tiny 6 platform. Also, because they have a third track they always have one train sitting there in the station waiting at the end of the game.
They do hold the 6 train in the station when the crowd starts to arrive but that's only if it happens to be there. If it's not there you end up having a dangerously overcrowded platform with no train, with just those two tiny stairways to get up there.