Interesting. So Koji said that Susan Calloway's sections are Hydaelyn's voice telling the races why they must suffer, right? I'm not sure how anyone is supposed to conclude that Hydaelyn is a benevolent goddess based on free will from that. Sounds more like some of the worst excesses of the Catholic Church if I'm honest.
It's a great song - one of my favourites since 1.0 - but I've never seen it as a hopeful, uplifting song. And I have been vaguely suspicious of Hydaelyn since the fight against Ultimate Weapon in the Praetorium. She didn't come across to me as a loving Mother Goddess, more of an obsessed, rather broken avatar who only cares about one thing. There hasn't been anything in the story so far to persuade me otherwise. If it turns out she IS a benevolent Mother Goddess, great, but the writing of the story better be convincing. At this moment everything is pointing in a different direction for me.
I would also like to mention the passionate debates before Shadowbringers when the people who were adamant that Hydaelyn couldn't be a primal were very much left with egg on their faces. Don't state things as absolutes until you absolutely know they're absolutes. Speculate by all means. Which is what I'm about to do.
Ramuh's words to us before we fight him have always troubled me. I'm paraphrasing but he says that Light and Dark weren't separated until men interfered. I think this may mean that the Summoning of Zodiark caused the split, and the reason it caused the split is somehow to do with the Fourteenth refusing to take part and leaving. If the full Convocation had been involved, they would have summoned the true Will of the Star, an entity where Light and Dark were in balance. And it's going to be on us to put this right.
This is all speculation but, based on the information I have right now, I feel like it's an elegant solution. Both Zodiark and Hydaelyn are 'wrong things' with agendas that are not ultimately beneficial to the star, and we somehow have to merge them or send them back where they came from. Or both