This is football and things can change very fast. The point difference is not much between Bayern Leverkusen and Bayern Munich. Bayern Leverkusen has lost Bofiface to the Nigerian national team for the Afcon tournament and if they are not prepared go cover for his absent it might really affect them since he has been scoring lots of goals for them. I just hope his absence won't cost them the too spot in the league table.
Victor Boniface has indeed become Leverkusen's mainstay striker this season and if he is absent from defending his country at the AFCON event it will clearly reduce Leverkusen's goal productivity slightly. But I don't think that has much of an impact because Leverkusen still has several players who can do the same job as Victor Boniface, for example Florian Wirtz, Jeremie Frimpong and Alex Grimaldo, even though they are not strikers, they can do similar tasks.
Now maintaining a place at the top will be much more difficult because Bayern Munich has not given up at all and they continue to make progress that makes the team better. They have also made player transfers this January to strengthen their squad. Harry Kane is also still very productive so Bayern Munich has no weaknesses in being able to win every match and maybe when they face Leverkusen again it will be a determinant of who will lead the standings. Even if Leverkusen loses and if the result is a draw then Leverkusen will still be completely dominated.