I don't think that Warren giving up part of his soul is relevant anymore, seeing as how mutants can be resurrected with their souls intact.
I still think that Warren will have to appear in a new unrevealed DoX tittle to get any meaningful panel time. I just don't see where he fits with any of the current book rosters, unless Archangel is put back in X-Force. Just my opinion, and I could be wrong.
Children of the Atom looks to be about the teen sidekicks, with Storm as leader. That doesn't seam to leave much panel time for Archangel. At least not according to what we have seen of the details of what the comic will be about so far.