Luiz Diaz made a very good move that I think he'll surely look back and be glad he did. At Liverpool, Mohammed Salah is the main main and with the arrival of Florian Wirtz and Hugo Etitike, Luiz Diaz would've probably been a regular on the bench but with this switch to Bayern Munich, he'll still be getting playing time while competing in biggest club competitions. Playing alongside Harry Kane in the attacking line of Bayern Munich, Luiz Diaz I think can form a good partnership with the England national team captain. With the arrival of the Colombian to Munich, I think it's now almost certain that the Bavarians will defend the German title next season.
I also think Bayern Munich will most likely successfully defend the trophy next season. Leverkusen, their strongest rivals, are currently undergoing a transition period, and Ten Hag will undoubtedly need time to find balance within his squad. Dortmund looked to be improving slightly last season, but I don't think they're strong enough to break Bayern Munich dominance. The signing of Luiz Diaz will further sharpen Kompany attack, he made the right decision by joining the Allianz Arena.
Given the changes made by the Bundesliga teams for next season, I don't think anyone doubts Bayern Munich's ability to defend their title. Indeed, none of the top Bundesliga teams have made significant changes to match Bayern Munich's strength.
Their success in acquiring Luiz Diaz certainly has the potential to significantly sharpen Bayern's attack. He is a highly qualified player, and the decision to join Bayern is certainly the right one for him, as he desires more playing time.
It's safe to say that next season's Bundesliga will once again belong to Bayern Munich, especially with the arrival of Luiz Diaz. This will undoubtedly make Bayern Munich's attack even more productive in scoring goals. Luiz Diaz is not only a quality player, as you mentioned, but he was a key player in Liverpool's Premier League title-winning campaign last season, and now he will be aiming to do the same for Bayern Munich.
My belief that Munich will win the Bundesliga again next season is justified, considering that Leverkusen's performance under Ten Hag hasn't shown any convincing improvement to compete with Munich next season. Likewise, Dortmund doesn't seem strong enough to face Munich's current strength under Kompany. As with Munich's recent transfer window, they are targeting the Champions League next season.