In my opinion, Bayern Munich made the biggest mistake by sending Nagelsmann. Of course, there will be some teams that want to evaluate this. It could be Tottenham, it could be Chelsea. The coming days will show us this. What I see is that he is a very good coach despite being a younger manager. Bayern will realize their mistake sooner or later.
Either it was a mistake or they did the right thing. Because they also appointed a coach like Thomas Tuchel to replace the role of Nagelsmann. Thomas Tuchel is also an experienced coach, so it is likely that under his direction Bayern Munich will become even more solid. But if Thomas Tuchel fails at Bayern Munich then the management will regret it because they made a hasty change of coach.
I don't think anybody will doubt the capacity of Thomas Tuchel because he is an outstanding coach that has a very rich credential and results. His main task now will be his ability to win the heart of the players and make them become loyal to him. He also has a very short time to study the players to identify their strength and weaknesses. The Bayern team is in a critical situation currently. They are in the process of losing their ten years dominance of the Bundesliga and their crucial champions league quarterfinal against Manchester is also around the corner.
I hope Tuchel's performance will not be measured based on this season's results because he needs so much time to understand and put the team in the position the management desires.
Apart from Tottenham, who are rumored to be interested in Nagelsmann, there is also Spanish giant Real Madrid who made an approach with the former Bayern Munich coach. Real Madrid projected Nagelsmann as a replacement for Ancelotti, who is currently also rumored to be the new manager of the Brazilian national team. Nagelsmann was considered appropriate to replace Ancelotti because he was a young coach who had successfully brought Bayern Munich to several titles.
If these rumors are true, I believe Nagelsmann will choose Real Madrid over Tottenham, because given the great history that Real Madrid has made and Nagelsmann can continue this tradition. To train Real Madrid is not easy and is exactly like training Bayern Munich, because the club has big players who sometimes have their own egos, but Nagelsmann has managed to keep the Bayern Munich squad solid and maybe that is also a consideration for Real Madrid's management
I suspect that Nagelsmann will not be out of job for a long time considering his performance in the two last two clubs he handled. Tottenham and Real Madrid are both good clubs that he can handle and have the right players and financial support. But in terms of history and respect Real Madrid will be the best option. Carlo Ancelotti is 63years old and I think it will be more healthier for him to switch to national team coaching because club management is more tasking and stressful. Ancelotti handling the Seleção will bring a lot of improvement to the Brazilian team.