Okay, that makes total sense. The "everyone will shift over" thing was what I was thinking based on her earlier explanation of the Astral Plane's existence/purpose and especially her broadcast, but I couldn't understand how that was "saving humanity." What I missed, or forgot, is she felt this was humanity's destiny to be pulled in and that it's good. Now, the primary places I'm getting stuck are:
1. Why she thought the Astral Plane ascension was inevitable while still blaming Yoseph for the Pandemic. (Hopefully I'm remembering correctly that she blamed him for the Pandemic.) Did she think he only caused the pain associated with the Pandemic and saw the Pandemic itself as good? And as File 12 establishes, Yoseph's activity seemed to be somehow causing the gates to be opening, making it seem like it was not inevitable. Did she not know this? However, Yoseph being responsible does not explain how the gates started appearing in the first place, so maybe I've misunderstood why the gates are disappearing at the end of the game. Maybe Yoseph only increased the volume, and although there are fewer now, they'll always keep coming, supporting Jena's idea.
2. She thought humanity would retain their humanity in her plan over Yoseph's. Her final line about who would be human in Yoseph's plan is really sticking out to me, given her plan seems to involve a lot of people turning into Chimera/disappearing into the Astral Plane. My guess: she thought that humans becoming Chimera/going to the Astral Plane was "natural" and part of the world's order, thus preserving humanity as it's supposed to be, while Yoseph's plan was "unnatural" due to him trying to fight against the invasion.
Also, this is a random question for anyone reading: Why did the Astral Plane affect everyone so strongly at the beginning of the game yet your character seems to handle being there fine after that moment? Maybe you still have to make sure you don't stay too long and they didn't want to always show you in pain? Or it has to do with the synchronization between you and your Legion, which gets better over time?
Thank you so much for that summary! I know I'm asking a lot, so no need to answer anything more. You really brought some of the pieces together for me.