I don't get why people keep harping on this like it's not an obvious fact. Yes, BB wanted to keep JG, but there was no way he was trading Brady coming off his greatest Superbowl victory. So he held onto Jimmy through the preseason, delaying a decision as long as he could - had Brady's play slipped this year, it's possible he would have moved TB instead. Possible, but still unlikely. Brady's play didn't slip; he has played at an MVP level this season. How can you trade away the face of your franchise in the midst of an MVP season?
Anyhow, one of them had to go; they would be too expensive to keep as a pair. The trade deadline was the last chance to get anything in return other than a compensatory pick. So JG was shipped out. Reluctantly, as BB himself said.
I don't see the great mystery in all of that, or why BB wouldn't have reached this exact conclusion with or without urging from Kraft. They ended up with the somewhat happy problem of having two stud QBs, and made the best of that circumstance. All this Wickersham nonsense is just uninformed people not understanding how the sequence of events worked out, and creating a narrative based on their fervent hope that it represented a great crisis within the organization. Wishful thinking on their part.