Brilliant move by Spence.
Already many tech (and other companies) have cancelled conventions and other events in Indiana, and while the NCAA can't really cancel the Final Four, since it's next week, they have said that they will seriously consider whether to hold future events in the state.
When the state of Arizona had a similar law proposed, the NFL said if you pass this law, we will NOT hold the Super Bowl in Phoenix. Guess what? Same thing this time.