I applaud Xabi Alonso for being able to bring Leverkusen to the lead in the Bundesliga even though there is only a 4 point difference with Munich. This means that Leverkusen's chance of becoming champions is not completely guaranteed, but I still appreciate Alonso as a coach who is able to make Leverkusen one of the strongest teams in the league today. And I agree with what you said that Tuchel could now focus on the Champions League because Munich is also one of the favorite teams to win. I think Xabi knows that the Champions League is a bit difficult this season so they will focus on the Bundesliga and getting the championship trophy.
Bayern Munich is also still one game behind Leverkusen so the gap in points seen now is four points, but if Bayern Munich's matches are the same as Leverkusen's number of matches and Munich can win. So the point gap between the two is just one, not four points, unless Munich cannot win in its 16th match in the Bundesliga. Apart from that, Leverkusen this season only competed in the European League apart from the Bundesliga, not in the Champions League like Munich. So the pressure these two teams have is certainly very different even though they often look the same in the Bundesliga.
There is no guarantee that Leverkusen will become champions, nor is there a guarantee that Bayern Munich will be able to defend the title they have won for more than a decade, yes everything is still very possible. Or maybe these two teams can even be shifted by the team ranked 3rd or 4th, yes even though it is difficult but with the remaining matches that exist it could happen, even though it looks impossible to me.
What is clear now is that there is new hope in the BUndesliga in Leverkusen, which was previously held by Borussia Dortmund but they always failed to realize the hope of being able to break the dominance of Bayern Munich in the race for the championship.