The 4 point gap from Bayern Munich with both having played 14 matches is still very possible for Leverkusen to narrow the gap. Although not dominating like last season, I think Leverkusen still has a serious threat. On the other hand Bayern Munich in the 15th week against Leipzig and Leverkusen against Feirburg, so it is considered quite fair with a fairly tough opponent. Maybe the difference is that Bayern Munich without Kane will have difficulties, while Leverkusen advantage is that they do not depend on 1 player, so they are more stable in attacking from any direction.
Four points lead can easily be levelled up by Bayern Leverkusen if they remain consistent in the race for the top spot because now that Harry Kane who is one of Bayern Munich top scorers is not available due to an injury, Bayern Munich will experience some little setback which Bayern Leverkusen can take advantage of and close the gap. Besides their next game against Leipzig will be tough unlike Bayern Leverkusen that is meeting Freiburg, though they can't be underrated but Bayern Leverkusen has the higher possibility of winning Freiburg. Bayern Munich may not continue at the top position for long because aside being that Harry Kane who is their lead scorer is not yet fit to play, Bayern Munich's defense is very accessible which their opponents can have an easy way to score. And Bayern Munich depended so much on Harry Kane that was why their performance after Harry Kane's injury began to decline but since Leverkusen don't depend much on a particular player, they will find it easier to score and win matches.