That's all well and good even if you don't think his body of work has been good (it has, in my book). But what does Middleton think? He did not see last season as a failure, and he surely signed off on every move, including Schwarber. And he also knows how close the Phillies came to signing Bichette (a deal they could have closed if he had the same checkbook and temperament as the Mets, not that I think that's necessarily a plus).
I would say there's maybe a 25% chance that Dombrowski steps down if this season goes badly and the team sets more of a rebuild course. 75% chance that Middleton is having a press conference - when they fire the manager, or in October, or both - where he says he trusts that his HOF-bound President to who took the team to a WS and two NL East titles is the guy he trusts to get them back, and as soon as next year.
In the short-term, I just don't think Dombrowki is under the kind of pressure that gets managers fired quickly, just like Stearns wasn't under the kind of pressure that would have made him fire Mendoza in Queens after 12 losses (and Mendoza stunk last year!). But a change is still gonna have to come sooner than later if this all continues.