As for Leverkusen, once they change their coach, I believe their performance will remain the same with their current squad. However, if they bring in more quality players, it could greatly help them. Still, I think the new coach taking over from Xabi Alonso may have the chance to give Bayern Munich a tough time.Since Bayern has won the Bundesliga now, they may aim to sign more quality players to strengthen their squad. If Bayern Munich succeeds in doing so, I don't think any team may challenge them effectively.
Munich with the same coach and with a little change in the team, might perform better next season. But Leverkusen with some changed players and a new coach, we still can't say how good they will be next season. They can be good from the start, but there is also a possibility that they will need time at the beginning of the season to adjust.
I just hope Munich doesn't lose to the rival teams. Dortmund is already in need, and if Leverkusen is not good enough next season, Munich will dominate.
A new coach and new players are always risky, the team may underperform. The more new players, the more time is needed for things to adapt to each other. If a new coach comes to a team, there will definitely be problems in the first few months. Teams make decisions based on these potential problems.
It's too early to say anything for next season, but in the summer the teams need to get used to each other and get into a good harmony. The vacation period shouldn't be too long
