Several months ago, I spoke to someone in the UND administration in a position to know whether such rumors are true. (Believe me, there are people on both sides of the Fighting Sioux nickname issue who'd love to believe that they are.) I was told that when the New York Times sent a reporter to Grand Forks to do a story about the nickname controversy, he inquired about the rumors he'd heard about Engelstad Arena and what might happen to it if the name changed.
He was provided with copies of all the documents relating to the ownership and control of the arena (which are public record, by the way). None of them contain a single word about a change in the arena's status if the Fighting Sioux nickname is changed.