I agree that Bayern Leverkusen should not be playing so seriously since they have beaten Bayern Munich for this season's Bundesliga title, but since they want to end this season unbeaten, they will be serious with every single match they play in the Bundesliga. Bayern Leverkusen needs to win or draw their last match in the Bundesliga this season to end the league unbeaten, and I believe Augsburg will not be a threat for Bayern Leverkusen.
Augsburg is a fairly easy opponent for Bayer Leverkusen for the final match of the season and will also make Bayer Leverkusen a team that has never lost for a full season in the Bundesliga. Because I don't think that Augsburg will be able to stop Bayer Leverkusen's ability to never lose so far, so this season it is certain that Bayer Leverkusen will end this season having never lost to any of its rivals in the Bundesliga. Apart from that, Bayer Leverkusen also still have to think about the final match at UEL this season because it is about who will get the trophy this season.