Didn't know where else to write this, seems like the perfect place.

In the trailer, we see two Aeriths: one is the living one with cloud, the other seems to be either dead or more likely comotose in Midgar. In Remake, we were shown Jessie's dad, who fell into the mako in the reactor and he was described as "stuck in the life stream". What if this is precisely the case with Zach's Aerith? She can't wake up because her soul is in another body? And maybe when the big moment happens at the end of the game, she'll wake up? Marlene's words in the trailer only seem to support this. "When she wakes up, tell her there's a scary man coming for her".