I know it didn't feel like it at the time, but it was probably a win-win for both sides.
It felt like Welker lost a bit at the end of his Patriots career, and it was clear BB didn't mind moving on.
We got Danny, and Jules emerged as the true Welker replacement. We win a Super Bowl within 2 years, and 2 in 3 years.
Welker got his full $12M with the Broncos and another chance to win a Super Bowl. I'm not sure he would have seen the second year of his deal here, let alone the incentives.
I do wonder if BB would have brought back Jules still if we re-signed Welker. My guess is yes because Dola was the Welker replacement, and we still re-signed Edelman for peanuts.