Welcome, looks like a lot of the league didn't re-up I hope we get some of those gm's back or some new ones.
Seems to be the typical pattern, at least in my FOF experience - about half of the new guys stick with it, then the next season about half of those new guys stick around. Plus, the first few leagues filled up quickly with the excitement of the new game, but the excitement wears off and they don't stick around. I was honestly surprised at how quickly the first leagues filled up, and expect the game to grow at a more reasonable pace now.
But yeah, hopefully we'll get the 70% here before too long!