Yes, that's how it is and we cannot intervene in Bayern Munich's decision. We all know that neither Ralf nor Tuchel are any different and this will only make Bayern Munich fall further behind, especially from Leverkusen. While Leverkusen will continue to advance with all parties defending, Bayern Munich, instead of superiority in quality, has instead lowered its standards.
Supposedly, if Bayern Munich doesn't have a better option than Tuchel then they can keep Tuchel and not let him go. We know that Tuchel will definitely take full responsibility for the results this season and will improve them next season. But if Bayern Munich still insists on bringing in Ralf then they have to be prepared for the possibility as you say and they have to forget about the Champions League.
Changing the coach is not a guarantee that the team's performance will immediately change for the better. In fact, changing the coach will be full of risks because all coaches have different coaching styles and they need suitable players to be able to carry out their strategy and it also takes time for the process.
Whether they want to or not, Bayern Munich's management has to make a decision after this season Tauchle was deemed to have failed to make Bayern Munich's performance better compared to last season.
It's not always about the risk that another coach might have the same issues to push the team to their maximum performance. The problem with Tuchel is that he can be a very strange person and it's weird that the clubs always find out after they signed him. He is a strange character and then often times the club bosses or owners don't want him to be around any longer. He was fired at PSG because he didn't get along with the director of sports back at the time. The same happened when he was the coach of Dortmund. Now the same is going to happen with Bayern Munich.
I think it is the right decision to sack him. Bayern didn't play well and their bread and butter still is the Bundesliga. They sucked big time and it is time for a change even when change is no guarantee that things will get better.