I have stated on many MANY occasions that Bill drafted Jimmy back in 2014 with the HOPE that by 2017/18, a time frame that would have marked the physical decline of 99% of most QB's, he would take over for a "retiring or declining Brady" It wasn't a radical thought, just common sense.
By 2016 or so, while Jimmy had proven he was a good QB, he was NEVER the "best" QB on the team, so there was never any thought he would be replacing Brady anytime during his rookie contract. He was NEVER a threat to replace Brady regardless of the conspiracy theories and narratives created at the time. While it was a surprise that Brady played so late into his career, it was NEVER a surprise that he would be the Pats QB as long as he was the best one on the roster. And the rest is history. Jimmy was traded for a top 40 pick which was about the best one could have expected.
Brady's departure was a LOT more complex than that. But IMHO, it was a natural chain of events which saw a remarkable 6 year run (14-19) which saw a remarkable FOUR superbowl appearances and 5 AFCCG's. People forget just how heavy the cost of those long runs are to the cap and rosters. From 16-19 the Pats went ALL IN to maximize that run. They did contracts and signed players that, by 2020, left them with a TOTALLY depleted roster and ZERO cap space.
Why fans or the media would think Brady would even want to be here in 2020 STILL boggles my mind. There was NOTHING here for him. Not money, not talent, not depth, AND add the fact his wife wanted to "go south". It was never about a "conspiracy", it was just TIME. It would have been painful to try and watch Tom play his final couple of seasons under those conditions.