I will not react excessively to the defeat of Bayern Munich or Dortmund because Bayern Munich has no real interest in this match because they should let go of the Bundesliga title which is no longer possible to achieve and focus on their match in the Champions League.
Meanwhile, Dortmund has much higher motivation because Dortmund is competing fiercely to finish in the top 4, so I think their victory is natural.
This season, Bayern Munich's performance has been very inconsistent, which is why they lost the Bundesliga title. Regarding the strength of the Bayern Munich team, I think they are quite capable, only consistency is their problem this season.
TBH, I actually don't want to say too much about Munich badness in yesterday's match, but the reasons you said are quite reasonable, maybe Munich will prioritize the UCL more than the Bundesliga title, but what makes more sense is that a big team has dominated the Bundesliga title for decades previously, Bayern Munich should not have destroyed their team's reputation with a humiliating defeat such as playing at home with bad results.
even though Bayern Munich could have held on to a score share draw to maintain its reputation with a better draw.
If indeed Bayern Munich has priority in the UCL, at least in the Bundesliga they won't perform badly.
let's see later in the match against Arsenal whether Bayern Munich can beat Arsenal and I will answer that Bayern Munich will definitely qualify for the semi finals.
however, it is not a guarantee that you can beat Arsenal and Tuchel must not underestimate Arsenal or else Arteta could avenge past defeats to further embarrass Bayern Munich.