It all depends on Bayern Munich whether they now get the right coach or not. The reason is that it is not easy to develop this team when in the process of looking for a coach there are no options to be had. Leverkusen will continue to lead the Bundesliga as long as Munich struggles to find the right coach. The problem is only with the coach, Tuchel will soon be fired and then next season with a new coach, matching with players, building cooperation which can be said to be quite difficult if the target is next season. Bayern Munich needs a process to return to stability. Leverkusen and Xabi Alonso are increasingly determined to welcome the Champions League. European teams in the future need to be wary of Leverkusen, their game is very dangerous in the hands of Xabi Alonso.
Tuchel is 99% certain to leave Bayern Munich next season, because of his inability to lift Bayern Munich's performance this season, besides losing the chance of the Bundesliga championship trophy is certainly an embarrassment for Munich at this time and certainly makes them have to take a tough decision to sack Tuchel in his first season, Bayern Munich previously had full hopes for Alonso to replace Tuchel as coach but after Alonso's decision to stay at Leverkusen certainly makes Munich now have to work hard to find another coach for next season.
At the moment there seems to be no active movement from Bayern Munich to approach other coaches and I think maybe they will do it in secret, it is quite interesting to see who the next Bayern Munich coach is and I think with Alonso staying at Leverkusen then we can be sure we will see tough competition in the Bundesliga next season, because as you said of course Bayern Munich will improve their squad later to become stronger And ready to compete after this season they failed miserably in the Bundesliga.