I thought DP40 was an epoxy primer?
I agree that with good clean metal, that a wipe down with laquer thinner should be good once the blast media is cleaned out.

I have used the etching primer before coating with DP40 on some pannels where I stripped the paint with sandpaper and I was concerned about the crevices that I could not get to really well. With media blasting this may not be an issue?