We have seen the dead come back already... The Kid for one... there is a bit of assumption that he died and then reanimated. I do not consider this out of the storyline of things.
I would guess that the "writers" decided that since they have not stated this fact in any way that that means they have license to play with this scenario. Meaning they are now free to say there is a "CURE" and even that all the dead are no longer the Living Dead but are actually Highly Contagious.
Bookmarks