It was really only Ole who truly chose to keep picking him. He didn't actually play under Mourinho that often (from memory he only started about 10 league games with a couple of those in the defence when Jose was trying to make a point after not being bought yet another defender), and Rangnick didn't really have any other options. This season he's played decently well so ETH has kept him in the first team for now (helped by Casemiro not getting going yet), but it's very early days. If it's still the same after a few months then that'll be a different story. Personally I doubt it but I'd love for him to prove me wrong by actually playing consistently well.