Not THAT crazy. Bennett was a good player for us and I doubt he'd mind coming back. He was a big piece of last year's team after Gronk went down and I don't think we get through to the Superbowl without him thanks to the Gronk injury.
I know it's not happening for a number of reasons, but most of the reasons cited in this thread so far aren't those reasons.
The real problem is that he's too expensive for what he does, we don't need him to be TE1 and he's too expensive to play TE2, the asset cost might be considerable and probably would not pay off, and he wouldn't be THAT big an upgrade over what we already have.