Winning the UCL trophy at this point shouldn't and wouldn't be the stress of Bayern Munich because personally I see that as stressing and a huge unrealistic pressure on the team, although they may look like it's very much achievable but the truth remains that in reality they may not be able to achieve the champion's league trophy not even with their experience and their depth, as the new coach needs sometime to be able to get on with his tactics and introduce it to the team such that they get to familiarize with it and produce results with it, all this will cost them some time which they may not have at the champions league but a good attempt at it wouldn't be a bad one.
I also think Bayern Munich should not worry too much about winning Champions League right now. They have good team but new coach needs time to teach them his way of playing. This takes time and trying to win Champions League too quickly can be too much pressure. It is better to let team learn and work together under new coach. Instead of trying to win Champions League they should aim to do their best and see how far they can go. This way team can focus on getting better and stronger which will help them succeed in the long run.
Of course, it will be very important for Bayern Munich to get used to their new coach. Because last year they followed very different strategies with Thomas Tuchel. Tuchel finished the league in third place without success and ended the league with a big disappointment for Bayern Munich. This year is the time to forget this disappointment he left behind. Although the squad is very good, there are still some problems. Especially in defense, as far as I can see, there are some problems.