A lot of those players were mad Carr was traded. The coaching staff and GM who were responsible for the decision to trade him are now unemployed. Lots of the Raiders fan base still like Carr and he wanted to stay there. If they kept the interim guy on, and their new rookie struggles (as expected), they could bring him back to be reunited.
Carr wasn’t traded. He was released. I have not seen any evidence of his former teammates being mad about that and i haven’t seen any raiders fans expressing sadness he’s not in Vegas.