When I start a sentence with "I imagine ... " whatever follows is speculation on my part, obviously, and you are welcome to dissent and claim something else if you wish.
I am of the opinion that coaching decisions are made by a small group, perhaps ten or so folks, and they don't let slip what they are discussing.
I also opine that this time of year is rife with rumors about coaching changes, some of which end up being right, some not, perhaps randomly because no one has any real "inside information".