Well, I think you trade Segura as a sell-high type proposition. If he's a 2.5 (FG) to 3.5 (BBRef) player again this year he's worth his salary. But I am trading him because I think he might not be able to do that again, and because 2B is not that hard a position to fill (and we can fill it with Didi. It's not like Segura is a great defensive 2B, he was just better than most of the other Phillies at other positions, and better there than at SS).
Problem is if most other teams see it that way too, than yeah, they won't want to pick up all his salary.
I just think there has to be one creative trade involving major leaguers and, sure, $, on both sides. Maybe it's Segura or Didi, maybe it's someone unexpected. Obviously the DH means there is less urgency/more ABs to go around if we carry an extra middle IF who can (theoretically) hit.