As I understand it, the Crux has a slightly shorter wheelbase and a shorter front-center vs. the Diverge. It also has a slightly higher BB.
So that will result in a bike that will feel livelier and more responsive than the Diverge…but compared to the old Crux, more stable and predictable.
On a spectrum of bikes with MTB on one side and Road bikes on the other (and gravel in the middle), the Diverge will be closer to the MTB side and the Crux will be closer to the Road side, but both still somewhere in the middle (if that makes sense).
Of course you will also be losing your Future Shock, which will probably be the most noticeable difference.