The NBA doesn't care about things like Nnaji, but the Bediako case does scare them. They would have to find a way to restructure the draft.
Every freshman that knows they would not get drafted, would declare for the NBA draft after their freshmen year. They are then declared undrafted NBA free agents. Under the Bediako rule, they would then still be allowed to come back to school, and if they bloom later in their college careers once they make the jump to the NBA they are free agents.
Think of late bloomers like Jaylin Williams or Cedric Coward. Or going back in time, Dion Waiters at Syracuse after his frosh year.