It will be interesting to see who gets the nod for GM.
Alderson has already told Rojas that he's coming back for another season. That means that the new GM won't be able to pick his manager.
I think Rojas is a lame duck and that Cohen and Alderson plan on hiring Theo Epstein after this upcoming season.
This could mean that Theo is already in discussions with Cohen/Alderson and might even be choosing the GM he inherits. I think Epstein will fill the President of Baseball Operations role, which, if he is whispering in Cohen's/Alderson's ear about a new GM hire, would enable that GM to stay in place, then pick his own manager for the 2022 season.
Maybe I'm crazy, but that's just my hunch.