I think it's admirable that Red, Griff and Gmac have such a strong sense of loyalty to JB (and they rightfully should).
I also can't fathom how I'd reconcile the career risk associated with that loyalty were I in their shoes.
Very few organizations choose a continuity hire when the long time leader overstays his welcome to the point it craters performance. And I imagine most, if not all, of those 3 assistant coaches will be forced to leave CNY if JB's replacement is not an alumnus (and they want to continue coaching high level hoops).
If that continuity hire is given the opportunity, the leash is going to be shorter than people unqualified to question coach at a presser. So maybe they're willing to roll the dice on an extra 2-3 years post JB retirement.