Bayer can now focus entirely on the Bundesliga, they don't have any prerequisites yet to hope that they can defend their champions title, but they have to try to do it, and for that they need to win all the matches, they can't lose points, so even though Bochum is not the easiest team, I expect Bayer to beat such an opponent. On the other hand, I doubt that Bayern will lose the difference that they were able to make.
I don't see the possibility of Leverkusen winning the title . Leverkusen's performance is not consistent. And that's why they are behind. Bayern Munich is still 6 points behind Leverkusen. Will Bayern munich lose 6 points in 8 matches ? Maybe bayern munichen will lose 6 points, but will Leverkusen win all their upcoming matches? This possibility is very low. If Leverkusen's performance is consistent, they had a small chance of becoming Bundesliga champions.
In the upcoming matches , Leverkusen will play against Mainz and Dortmund. These two teams are quite strong. It will be difficult for Leverkusen to win these two matches. Also, Freiburg and Augsburg are quite strong teams.