First Leverkusen often almost lost at the end of last season because they had already locked the title, so they could play without any burden and maybe they were not focused on getting a win, because in fact they also did some rotations at that time.
Leverkusen shown some early signals of success two seasons ago when Xabi Alonso took over the coach position in second half of season and helped them to end a crisis, ranked up high on Bundesliga ranking table. Success in a last season is a good upgrade of Leverkusen but they need to take Napoli case as a warning for themselves.
Napoli after winning Scudetto in an impressive season, suddenly lost their best and last season they failed to finish in top four of Serie A. Leverkusen will face with a new season with many challenge from opponents in Bundesliga as well as Champions League.
Although I also agree that Leverkusen's opponents next season will be very alert and they will start reading more deeply to face Leverkusen's strategy. Second, I agree with you that Bayern Munich does not depend at all on Leverkusen's performance, they must focus on themselves.
Every team have strength and weakness and it's not exception for Leverkusen. One season and one summer for a season preparation is enough for many clubs in Bundesliga to do many research on Leverkusen and they will be better prepared than the last season to deal with Leverkusen and beat the unbeaten team throughout the last season.
When Leverkusen can maintain a good performance like last season, but if Bayern Munich can perform better than them then the title will be won again by Bayern Munich. So they should not look at what other teams can do, but they must bring out the best abilities they have.
Biggest opponent in Bundesliga, Bayern Munich does not stay silent and they are improving their squad and very ready to beat Leverkusen and get a domestic league crown back as soon as possible. I am sure Bayern Munich don't plan to lose the trophy to Leverkusen in two consecutive seasons.