Is there a reason this still hasn’t been added back in? I think that having a ranked FFA playlist will help boost the population back up, giving those solo players a reason to stick around.
You were always able to find games in it on the original Halo, 3 even when the game was near it’s end. Most of the time, it was actually the most populated/played playlist, so it doesn’t make sense to exclude it from MCC.
A good way to implement this playlist would be to possibly lower the minimum player count needed to match, and keep the rank matching wide so you can always find a game, even if this means like rank 1-10s being able to match with 50s, but preferably tighter then that.