Munich will take revenge for their failure to win the title this season. I don't think they expected Leverkusen to be an unexpected variable and stop their dominance in the Bundesliga. They will certainly be better prepared next season and this will make the Bundesliga truly competitive.
If they ended up spending 100+ million euro just to get Kane after a season they "almost" lost, think about what they will do after they actually lose it. I am guessing that Bayern with their deep pockets could just turn this ship around completely and get rid of any of the old players that is not providing like they used to, such as kimmich and sane, those players may leave and someone better could take their spot.
This is why I believe that we are going to end up with something more and something bigger in the end. I get that things are not looking like they are doing all that crazy, but we should probably see Bayern getting the title back again next season. Xabi didn't make a mistake though, if they finish second, close to Bayern, that would still be fine.
Overall, the Bayern Munich players have no problems with their performance, but because this season in Tuchel hands they have created a different playing style. Bayern Munich does not feel comfortable with Tuchel strategy, we can see it clearly on the pitch how many Bayern players express this incompatibility. For next season although there will be no changes to the players as long as they get a suitable coach, the Bundesliga can be controlled again. Xabi is clearly superior in terms of tactics to Tuchel and that is the main reason why Bayern Munich cannot provide resistance in the Bundesliga. Next season Leverkusen will still be with Xabi Alonso and in a state ready to receive Munich revenge. As long as Bayern Munich is not in the right hands, of course Leverkusen will still benefit.