It is understandable feeling because their manager is new and they are starting a fresh page which means that it will be a trouble to have that type of reset button hit right before meeting City. Whereas City has been building this team for years to get that UCL title, doesn't mean they will, there is a good chance they won't and they will lose instead and that's understandable, but that doesn't mean that they will lose, it's going to be a tough situation in the end and I believe that we shouldn't really be worried about it at all.
There will be 3 matches for Bayern before the match against Manchester City, 2 of them in the Bundesliga and the third in the German Cup. Therefore, Tuchel has some tests that could give him the ability to find the best lineup for the match against Manchester City. However, he's an experienced coach who knows both German and English teams very well, so I think the possibility of Bayern qualifying over Manchester City remains high, and even better than the case where Nagelsmann was the coach.
Real Madrid versus Napoli in the final, right? Real might be the frontrunner to snatch that trophy, but don't underestimate Napoli. They've been on fire in every game, and with that massive 19-point lead in Serie A, it's all eyes on the Champions League now. Plus, Gennaro Gattuso has been straight-up killin' it as their coach.
I doubt Real Madrid can reach the final this season, although I hope so. Realistically, there are few teams that look better than them, especially when they will face the winner from Bayern and Manchester City if they qualify for the semi final. On the other hand, Napoli seem very powerful and ambitious team this season. We also shouldn't forget that they have reached this stage for the first time in their history.