I think you probably nailed it. They had to make sure they had the 3 freshman on board first. Cynically, there is something called a "bait and switch". Just a guess, I have no clue about the deadlines, etc., but probably timed to lessen damage to recruiting.
I meant last years, Green, Mannion and Nnaji. I'm saying from the outside it looks like they thought last year might be a really good team with those 3 kids, so they didn't want to self impose last year. Unless there's some new info in the notice of allegations, if they really did this because of serious lapses in judgement, that happened quite awhile ago and they knew about it for quite awhile.
Generally schools self impose to try and make it look better, we're taking a hit on our own to show the NCAA we're serious. the problem to me is this looks like they simply picked a year they don't expect to be very good, and/or think the season might not be finished anyways due to Covid so might as well self impose?
Maybe there's other stuff they know about that I don't but based on what I'm aware of the timing seems odd.
Just like how in Sept Coach K was saying they HAD to play this season for the good of the kids, then his team started slowly and suddenly he wants to end the season.