If it happens this week - or even this season - it's his own ego's fault.
He was asked to bring in a new OC, if not staff, and give up the play-calling but he stubbornly held up their end-of-season success as proof he didn't need to do it.
Had he done that, he'd have likely bought himself an extra season...
Sounds like "for cause" insubordination to me. He's costing himself a lot of money.