
Originally Posted by
polyphonica
With the scene of our mystery Crystal Tower person holding a copy of Heavensward (along with the other inner-shard travel hint in the trailer) I think it pretty much confirms the time travel "gimmick" that seems likely to set the stage for the story:
We can pretty-safely assume that the Crystal Tower in the First is the same as the one on the Source, but gone back in time from the future. G'raha Tia awoke to see that disaster had befallen the world and studied history (including the book Heavensward and other chronicles of the WoL) to narrow down history's turning point and a way to prevent the calamity. He then warped the Crystal Tower back through time and space over to the First before this critical junction in history, but since he probably couldn't tune the time travel precisely, he erred on the side of caution and overshot. Then, he just waited for the right moment to bring the WoL and Scions over.
Thanks to the temporal paradox (and the tower's existing powers), the two Crystal Towers can essentially serve as an interdimensional bridge between shards, which is what will allow us to freely teleport there and back. I assume he had to warp the Scions first so that people in our era would have the necessary hints so they could "tune" the Crystal Tower to be in alignment with the one over there and make the dimensional bridging work. Perhaps once this bridge is secured, they'll be able to warp the Scion bodies over to rejoin their souls already on the other side (since they appear to be in their own bodies while they're there).
So the history that needs to be unwritten (per all the trailers) isn't our past, but G'raha's past -- it's still our future. With this intervention, we'll be avoiding the calamity we otherwise would have walked into, and instead be able to learn the truth about Hydaelyn, Zodiark, the Ascians, and the new way forward -- whatever that will be.
Yes, there's a Live Letter on Friday afternoon (3pm PDT), but I'm not expecting to get too much more lore-related hints at that one. They mentioned it'd cover some of the crafting/gathering content/changes, so probably more things like that.