Yeah dude, really bad.
For starters, there hasn't been a 6 seed in the final 4 since 1992.
Here's how futures bets are set to begin with. Oddmakers get together and determine the actual chances of a team completing that bet. So in reality, let's say SMU was 20-1, which sounds more reasonable. Then they figure out what the worst possible number they can put on it, but still get action on it. In this case it was right around 7-1, and bettors took the bait. That extra 13-1 in equity goes right in to the book's pocket.
They got away with that number even more because SMU is hyped up big right now. And future bets are fun, and people like them.
Even if SMU does it, the books will profit off of the future bets on Duke, Nova, Baylor, UVA, etc and still come out ahead.
I wanna own an offshore book that just does futures soooo bad.