I think if he wins the CL we'll go for him, it'll be too big an opportunity to turn down.
Whilst we shouldn't move off the basis of 2 games, I think a CL at Bayern would be what makes his stint a hit (otherwise its a clearly a flop given all the domestic cup exits, skimming the Bundasliga last season wasn't convincing and he completely fell away from Leverkusen this year).
I get that we need more pragmatism, but that's relative to the shitshow we've seen this season. If we take a clean slate, I don't want an overly cautious manager and want to see a 433 variant with squash buckling football. If Tuchel can apply the Dortmund style that made him so sought after, I'd be more positive about the appointment. All in all, we can do a lot worse than him.