I'm not going to say that we expect to see a miracle from Thomas Tuchel and his payers in the next season but the fact about ith coach is mostly about the experience he got in the champions league which can be usually for Bayern Munich which is the main reason for them to hire this coach.
The UEFA Champions League is an extremely difficult competition in which the best four teams from each European league compete for the campaign championship. Bayern Munich is a challenging contender for the league title; they frequently lose a game. Perhaps during Julian Nagelsmann's administration at the Allianz Arena, the squad functioned effectively, but after bringing in Thomas Tuchel, the club began performing terribly. In his first season as Bayern Munich manager, Thomas Tuchel won the Bundesliga despite the club's terrible performance.
I don't think hiring Thomas Tuchel was the right move from Bayern. He may have experience but I don't think he's the kind of manager that they like. Bayern struggled after Tuchel took over. While that may be because he's just coming, it may also be because he's not capable of the task. The fact that a manager is experienced doesn't mean he will be successful at any club he goes.
Based on the reinforcements that Bayern are trying to get this summer, they may win the league easily but they won't get to the semi final fof the champions league. There will be no real difference between Nagelsmann's Bayern Munich and Tuchel's