You seem to be set in your dislike for him and I don't think I'll change your viewpoint but my thoughts are
1. The club will have a lot more background info on what happened with these clubs than we ever will. They'll talk to their sources, talk to Tuchel and make a decision that's going to be a lot more informed than us speculating on the Caf about him falling out with the board in two years.
2. Pep himself fell out with the board at Barca and then left Bayern again after being burned out and gotten smashed by RM. Would you avoid him?
3. You'd need to look into each of his clubs independently and investigate why he fell out.
Mainz: No sources seem to have inside info here. He spent 5 years, decided he couldn't take them further and chose to quit himself after seeing out his contract.
Dortmund: Drama lies here. Tension was already brewing after the club sold a bunch of key players (Gundo, Mkhi etc.). Didn't like the fact that he wasn't even consulted for signing some others. He fell out with the players after the whole Dortmund bus attack incident.
https://www.dailymail.co.uk/sport/f...How-Thomas-Tuchel-fell-Borussia-Dortmund.html
PSG: Things were going fine for him in the league but he complained about political drama (keeping Mbappe and Neymar happy). My understanding here is that he didn't actually fall out - his contract was up and the powers that be didn't like the football that he was playing with them and that he didn't win the CL so sacked him.
https://archive.is/YjpOj and
https://www.footballtransfers.com/u...gue/2021/09/why-did-psg-sack-thomas-tuchel-us
Chelsea: Things went great under Abramovich. Boehly brought a wrecking ball to the finely tuned machine that was the Chelsea backroom strategy. I find it impossible to blame him for the sack. Most Chelsea fans were sad that he left and will probably take him back with open arms.
Bayern: I'll let you decide since it's the current season. They're already in boardroom political turmoil and sacked one competent coach (Nagelsmann) for seemingly no reason. I won't blame Tuchel for falling out here either.