If Bayern fails to defend the title, of course Tuchel will be the person most to blame, but we must also realize that the competition for the Bundesliga title this season is much fiercer than the previous season because the Leverkusen team currently has strength comparable to Bayern.
I think the rumors about Jurgen Klopp are groundless because Jurgen Klopp has said that he wants to rest first, of course next season he will not manage the team.
It seems that Bayern in Tuchel's hands is also very strong and even stronger than in the previous season, but they are inconsistent and fierce competition from other top Bundesliga teams is making it quite difficult for Tuchel this season.
You are right if Bayern doesn't win the title, some people might blame Tuchel. But we should remember that the competition this season is much harder than before. The Leverkusen team is also very strong, like Bayern. So it's not fair to only blame Tuchel. There are other things that affect the team performance. Overall Tuchel has shown that Bayern is a strong team with him as the coach. But the other top teams in the Bundesliga and the team inconsistency have made it hard for him this season.