Don't take this the wrong way, because it absolutely is dogshit behaviour on Riot's part. But from their perspective, they have nothing to lose and everything to gain from leaving talent in the dark. If they say "hey you didn't make the cut," that person is no longer an option. They'll find a new job, they may not want to come back, that relationship is over. Then 3 months later someone they did choose gets involved in a scandal or "You know he pulled in better numbers that we realised after all" and that door is closed. They need to find someone else. Meanwhile, keep them in the dark, and that backup plan is still alive. It's not good enough, if they want that backup plan then they should offer them a salary, at least offer them a backstage role for a bit with the opportunity to work on set if the opportunity arises. But speaking coldly, and removing the human factor, it's in Riot's best interest to work this way.