Firstly, I don't think there is any significant chance that Pogba will stay at Manchester United and probably it's even better, because it seems that the management of Manchester United is already tired of this suspended situation.
I myself don't know how big the chance of Pogba to stay or to leave is. There are many cases on transfer window that a payer decides to stay although he is rumored to leave and linked with some big teams. The strong candidate to sign Pogba is Real Madrid, but Real Management seems to focus on signing strikers. If they sign both Mbappe and Haaland, I am not sure they want to spend much money for a midfielder.
Pochettino is quite charismatic for the level of the current Manchester United squad, where only Cristiano Ronaldo can be called a superstar.
Charismatic is the nature of someone, doesn't depend on what team he manages. I never heard that Pochettino is well known for his charismatic style in managing a team. I don't underestimate his ability in managing a club, but in my opinion he doesn't really suit with Man United players' characteristics. However, not really a bad idea if Man United management wants to hire him for 1-2 seasons.