He wasn't happy with Mourinho, that's as much fact.I understand David, but Pogba? Clearly wasn't happy with him in the summer.
However, doesn't make sense he's going to stay for the sake of the new manager's eyes if we end in Europe league while Barca is knocking on the door. He's 26, that's his prime and he should be winning things now, not sure him or Raiola will be entertaining the idea of new 2-3 years project that they don't if it will succeed or not while they have better alternative.
It was easy to handle one season at Europe League but to be at it again and to regress like that will make the star players that want to win consider their options. The team won't look like winning anything big anytime soon if it happens.