what are these?According to Wilner, pac 12 schools can no longer participate in these.

Also says no div 2 opponents in the "Regular season" Does this mean you can play them in the non conference season?

They're pretty rare for a P6 school to have. I can't imagine there were many at all last year (maybe Utah @ Kentucky?). Teams have a lot of home "buy" games where it pays a low level opponent for a game. Basically it's buying an easy win. Common in football too. This rule change basically says that that P12 teams can't be on a "sell" side of one of those games where they're getting paid for a game on the road as part of a one-off.