Although i don't think we should have booed him, he's shown his cards with some of the things he's said. Obviously he put the work in at City, but it was clear from the first season that he was a mard-arse when he wasn't playing. But it's easy to forget that City and Pep made him into this player, he was good before he joined but Pep made him brilliant. If you aren't able to respect the process that got you there, fuck off to Bayern and sit on their bench as well.
I don't think this is the end for him, time away from the squad and seeing that other managers also don't trust him surely must tell him he needs to buck up. But it all depends on him, he's not exactly proven himself to be able to take criticism and setbacks.