We know Kyler was practicing before the Dallas game and it was leaked that he was expected to be available to play.
Then, he goes on IR. Which is the worst possible thing to happen if you have made the decision to move on from Kyler and hope for a trade. If they decided to trade him, then they should've played him. Just like Gannon said they were going to. Kyler would have played like he has the rest of his career, a middle of the pack passer and an above average runner. Maybe he would've gotten hurt again, who knows. But, we would almost certainly have more leverage for a trade than we do know.
Whatever happened in the two to three days from Gannon being at the podium after the Dallas win to Brissett being named the starter and Kyler going on IR is why this team went completely south. At least in my mind, the time line fits with the team quitting on Gannon and the rest of his staff.
Just my .02 cents.