Quite possibly. Based on what we know, though, he wanted to stay in Boston. And as has been pointed out, bad things can happen in one year. It was a good deal all the way around.
They did also sign those extensions with Sale and Bogey.
You could tell JH was putting on the clampers a bit because of the tax situation, since DD didn't replace Kimbrel or Kelly.
I don't disagree with you. At the same time, I don't think it's really fair to dismiss the Devers extension as "something they had to do". Have to give them credit for doing the right thing there.