I would not be surprised to see the MSG as part of the ACC tourney rotation. The tourney will still mostly end up in Greensboro/Charlotte, with rotations through ATL, DC and NYC.
The C7/Big East has the contract with MSG, but MSG has out clauses if the NBE can't meet attendance requirements. IMO, they won't, as GTown is really the only big attendance driver left. No more SYR, ND, UCOnn, Lville, Pitt, who were likjly 5 of the top six attendance drivers. The NBE will need StJohns, Seton Hall, Xavier, Villanova to really step up to fill the garden on Friday and Saturday night of tournament weekend.