I don't hear about rumours related to German teams these days. Bayern Munich don't make many transfers so I'm already accustomed to that but it shouldn't be the same for Dortmund as well. They need to continue to make the squad stronger to keep their current level in the Bundesliga at worst. Otherwise they can even be under the threat of losing the second place in the league table. I don't say anything about the championship because it is obvious that Bayern Munich have a huge chance to be dominant again.
True, among other Bundesliga clubs Bayern Munich has a squad above the other contestants. I can also say that they will come out again as champions in the competition next season.
But in the Champions League, I have a little doubt about them, because they have a squad that is not much different, only Mane being a new name is their biggest transfer. I have a little doubt that they will be able to compete in the Champions League next season.
Bayern Munich is not going to have any problems winning the Bundesliga title at all. They don't have any competitors who will be able to give them a decent fight.
But in the Champions League, they have a lot of competition and there are teams that are better than Bayern Munich in a lot of aspects. So they will obviously find it hard to win the Champions League.
I think the case of Bayern Munich has become like PSG. Bayern Munich also does not face hard competition in the league and that does not prepare them well enough going into the Champions League.