The only part that makes it difficult for me to believe is that Kyler looks extremely happy AND engaged...more than ever before. If he was just muddling through a bad situation, even with agreements on all sides, I think his attitude would still be salty.
Now, what may be more plausible, is that they have an agreement if things don't go well when he comes back, either his performance or how he fits into the offense, then they would look to trade him and let him go...But for now all parties have to give a 100% fair chance to succeed.