Honestly, the defeat was really a painful thing for Leverkusen because, seriously, it really broke a great record Leverkusen wanted to set in the Europa competition. If Atalanta had not defeated them, it would have been a great achievement for them to win both the Bundesliga and Europa League without being unbeaten. The way Atalanta defeated Leverkusen in the final match was surprising to many of us because I don't think many of us expected something like that to happen. Now that Leverkusen is playing in the Champions League next season, let's just wait and see how their form will look.
Leverkusen may be strong next season, but I don't think that an unbeaten streak will happen again. The Champions League is really different from the Europa League; the Champions League is always a tough competition. In the Bundesliga, I don't think they will have the chance to repeat an unbeaten season again.
Indeed, I myself thought that Leverkusen would be able to beat Atalanta easily, but in reality Leverkusen was made difficult by Atalanta so that Atalanta was able to beat Leverkusen with a very good score, I thought Leverkusen would dominate in the second half but this did not happen. Leverkusen's unbeaten record was broken by Atalanta so that Atalanta was the only team able to beat Leverkusen with a landslide score, but even though Leverkusen had failed to beat Atalanta, it was a very good achievement for Leverkusen because it had dominated the Bundesliga.
What you say is right, especially Bayern Munich, which will definitely not let them continue to dominate, will definitely try to beat Leverkusen. It's tough for Leverkusen to become an unbeatable team again, if Leverkusen can still maintain that performance.