I realize what you are saying, but I have to say that if we see Justin again, and it's not in a memory or something like that, I'll be disappointed.
Jim has made it pretty clear that Justin is gone. Granted that may mean his spirit/soul, but if his body is being used by someone else, It'll be too similar to the CT/Luccio thing, and it's a "been there, done that" kind of thing.