I have no doubt about Bayern winning the league this season. Imagine with 9 point difference, that mean they have to lose like 3 match for Leverkusen to meet them. Even if they do what is the assurance that Leverkusen will win all his matches as well.
The points gap that you see is the gap where Leverkusen still has not played for the 28th game this season and if Leverkusen can win at Heidenheim's home, then the points gap will return to six as before. But after seeing the match in the first half for Heidenheim vs Leverkusen, it seems that Leverkusen will have a little difficulty in winning today's match and even if Leverkusen can win, I don't think it will be with a higher number of goals. But if today's match ends in a draw, Leverkusen must forget about the Bundesliga title race for this season.