Maybe but it might all be a lot more benign than we think.
2021, things are promising. Mac looks solid. Bill and Kraft are on the same page, Mac could be "the guy".
2022, Josh leaves and takes tons of coaches with him. Bill brings back Matt and Joe and they decide to simplify the offense. Makes Mac mad, Mac is vocal about how it's bad for him, the offense overall looks kind of crummy.
2023, Kraft tells Bill "your experiment with Matt and Joe backfired last year and Mac suffered for it, go back to the old system that worked the year prior, bring back BOB to run it and Mac should return to form." Bill privately says you're right, it didn't really go the way I envisioned but I don't think Mac really is as good as we thought he was in 2021. But I'll give him this year to show us what he's got before we have to commit to him. Turns out Mac sucks, the 2023 offense is even worse than 2022 despite running things the way Mac wanted, Mac regresses terribly.
Now that doesn't necessarily mean that Bill is being held against his will starting a QB he hates, it could have been more gentlemanly than that. Hopefully Kraft sees Mac sucks and is glad Bill did not spend tons of cash on what would have been a bad year regardless. And maybe Bill also didn't necessarily see a far better QB alternative available anyway that he didn't have to spend an arm and a leg on, so trying Mac one more year was worth a shot. If it is all kind of above-board then I could see Bill staying on and picking a new QB and basically doing 2021 over again - draft a QB in the first, spending a bunch of cash on pieces and seeing how you net out long term.