This option makes for an interesting story, in any event. Imagine if someone's soul is off in heaven (or whatever), and Ilyanna manages to find it and lead it back to the 616 universe in his cross-dimensional traipsing about, only for the soul to find out that there's a person in a copy of their body, with a copy of their memories (up to the moment of their death) living their life! Nobody 'misses them' because they thought they were already back! Their family, friends, etc. have accepted this new person as the continuation of them, even though it was just a copy!
That said, it feels like we *just* got rid of the O5 and teen Jimmy and old man Logan and various other annoying duplicates of people running around. I'm pretty sure that I wouldn't want a ton more of them...
There are few mutants with spiritual or mystical powers that would allow them to 'fetch souls' to inhabit these husks, with Ilyanna being the most common choice, and Wycked the most specifically-appropriate choice to get involved in a resurrection-machine-gambit. Maybe Dead Girl, from X-Statix? Dani Moonstar, with her Valkyrie death-sense? Certainly Selene... (Not that this seems like the sort of thing she should be trusted with, although Selene and Sinister, working together on their *own* resurrection process, Sinister providing the artificially-aged-up clone bodies, and Selene the souls to re-occupy them, could be a neat sub-plot for the return of the sorts of mutants that the Krakoans wouldn't be a big hurry to resurrect...)