I think he's been in the public eye long enough to know that he is an honorable person.
I'm not concerned, he's seen how quickly you can go from hero to zero as a manager. He's seen how some clubs are toxic. He's also seen how managers have forged a good career for themselves at this club, and the support and opportunities given.
I don't think he would even think about the Man Utd job right now, if offered, because the expectation and pressure is too high for a rookie manager, and he knows it. Give it 4 years he'd find it hard to turn down.
He is smart enough to know he is in a great role, could get a promotion on his CV this season, if not maybe next season. Either way, he knows the chairman will back him, he won't get that in many other clubs, including West Ham and Spurs.
Premier League is different gravy, the pressure is intense, tactics have to be spot on, managing international quality players and keeping them happy isn't easy, he knows this. He knows that he is putting in the groundwork for his management career right now, he can make mistakes without them being terminal, which might not be the case at somewhere like West Ham.
I have 99% confidence he will be with us next season, and I'm fairly confident the season after, but it'll get tough to keep him beyond that 2 1/2 year mark. We would have to be in the prem, and pushing for a european spot to keep him. That would require a huge transformation from there we were when he arrived and likely a lot of Gibson-dollars, to invest in the necessary quality.
Let's just enjoy it while he is here.