A huge announcement broke the internet last Thursday. Jeff Kaplan, the lead designer of Overwatch, announced several changes to Overwatch. One of those changes is rotating hero pools. Think of it like map pools rotating each season in competitive, except it is on a weekly basis with heroes. Not only are map pools rotating in competitive, but also heroes. As soon as the developer update released, Overwatch League released a blog detailing how hero pools are going to work for the league.
It's no secret that Pantheon is a problem. He has been banned in all but one single Play-In Stage game, and was, of course, immediately first picked and won the game. But this has been problematic before, and it needs to be fixed.