He'll be doing one column a week and doesn't have to be on call like he was at SI when breaking news happens. It's a semi-retirement gig, where he can be the grey-haired éminence grise rather than the face of the organization. It will be a lot less work and pressure.
The "kids" at MMQB will be flying solo, with no more "I'd rather hear what Peter King has to say" pressure from readers. At NBC, he'll be one guy rather than the man in charge, so he won't be blocking any other writers from carving out their own space...