I have no problem with this. How many regular students go to college, realize its not the right place for them and transfer. I think you should allow the same thing for athletes.
I don't think it will be all bad for mid-majors either. It might be a recruiting tool. "Look, you have offers from Iowa, Iowa State, Minnesota, etc. I think you're better than that. Why don't you come to UNI for a year, dominate the Mo Valley and then if you don't enjoy it, watch the Dukes, Kentuckys and North Carolinas come calling. Kind of their own version of 1 and done.
Plus, for every transfer that goes to the bigger school, that is one fewer recruit that they can bring in.