I don't think it makes sense to grant basketball (or hockey) players an extra year of eligibility just because the tournament was cancelled. For spring sports (softball, baseball, lacrosse, etc.) I would support that, because over half their seasons are cancelled, though.
Michigan loses Teske and Simpson, which is significant to be sure, but I think the team will be better and a BigTen contender next year with more depth. Austin Davis is getting his 5th year here. I hope Castleton will stay but wouldn't blame him if he transfers. I think Nunez will transfer and don't know about Bajema. Everyone else should be back.
The incoming players are Zeb Jackson, a highly rated combo guard, Hunter Dickinson, a highly rated center, Isaiah Todd is one of the top forwards in the country, Terrance Williams is another top 100 forward, and Jace Howard is Juwan's son, who got some other decent offers (Dayton, Saint Louis, San Diego State), but will presumably walk on. They're also the favorite for one of the top shooting guards, Josh Christopher.
My early expectation for the lineup is DeJulius, Christopher / Brooks, Wagner, Livers, and center is a tossup with Dickinson, Davis, and Castleton. I would expect Todd, Johns, and maybe Jackson to be other main rotation players. Regardless, I think the starters will play less than usual because there is so much depth, but we'll see....
The big non-con games so far are the return game to Oregon, and they're in the NYC tournament with Baylor, NC State, and Villanova.