Will after effects take advantage of dual CPU's?

Take careful note of Mylenium's advice here. Clock speed is much more important than core count for Ae. Obviously it depends what generation of i7 you're moving from - but 2.2GHz is not much more than half the clock speed of a good i7 or i9 chip. As far as Ae work is concerned - you could easily be heading for a downgrade.
You might want to spend some time reading related articles here: https://www.pugetsystems.com/

They're a well regarded system builder who have done a lot of testing into hardware for Ae and related applications.

Long and short: No. AE uses a full buffer renderer, meaning it cannot distribute calculations into buckets/ tiles/ scanlines plus due to general limitations in video processing such as linear file access and sequential calculations for temporal consistency there is only so much room to optimize for multithreading and parallel processing to begin with. In fact since per-core-efficiency is lower on Xeons and TurboBoost doesn't work the same way as on iX processors overall performance may be worse. Using such a setup really only makes sense for extensive 3D work and/ or other compositing tools like Nuke, but not AE.

Mylenium