It was obvious that the Raiders were done with tackle Trent Brown. So why did he agree to re-do his contract when he simply could have dug in and waited to be cut?
He wanted to return to the Patriots, and the Patriots wanted him back. Given that the Raiders could have squatted on Brown through the draft, there may have been few if any options for Brown when he finally was released.
For now, the Patriots wanted him and were willing to give the Raiders what they wanted. That may not have lasted, if Brown hadn’t been available and if the Patriots had to look elsewhere.
It also would have been hard for Brown to maximize his earnings as a free agent this year, given the reduced cap and the fact he didn’t play much last year. The Patriots know him better than anyone. They wanted him. He wanted them. It made sense for him to take less, and it made sense for the Patriots to make the trade.
Brown now can do what he did in 2018 — he can have a big year, and he can become a free agent again. The Patriots once again would get compensatory draft-pick compensation for Brown if he leaves via free agency, again.