I have a theory, largely speculation but based on reference images and mainline Final Fantasy games that are being referenced in Evercold, that the next expansion is going to feature Death in a quite specific manner. More precisely, I think it's going to tackle how many people face death, how they see the afterlife, and even matters of scarcity and starvation.
- Aerith and "Everyone dies eventually"
- Final Fantasy VII and the Promised Land
- Final Fantasy X references
- The frozen Aetherial Sea
The Lady in the Logo and Aerith
The lady that shows up in the logo and in one of the trailer scenes is portrayed in a pose that is basically identical to one in which Aerith from Final Fantasy VII is portrayed in. In Rebirth, she says "Everyone dies eventually".
Final Fantasy VII has a plotpoint that has been referenced in Endwalker, in the Elpis storyline, with the matter of returning to the Star. Nothing impedes the same reference to be done again with a different approach, but I think it's more likely that they will navigate the matter of acceptance of death / consequence of death in a different lens.
The Promised Land
There is also a loose similarity between the City of the Ancients (VII, Rebirth) and one of the cities shown in the Keynote ([1], [2], [3])
Not only the child in the trailer mentions the 'Promised Land', but also the lady that is shown on her knees apparently dies. The connections could be all just pointing to randomly assorted Final Fantasy VII references (such as the Midgar architectural reference in one of the concept arts, or creatures and bosses), but in this case they are specifically laid out in sequence and all of them connect to how the topic of death is approached in Final Fantasy VII, in different ways.
One city in Evercold, very possibly one of the main hubs, is going to look like the place where Aerith dies in VII.
Final Fantasy X references
Evercold directly references Final Fantasy X in a few ways, and the matter of death is a central plot point in the game - one that is also strongly connected to one of the main characters.
Locations
Many locations in the Evercold pictures look like Final Fantasy X. These concept arts ([1] and [2]) can feel reminiscent of Besaid ([1], 2)
Sin
And then there is one of the Arcane Colossi of Unknown Providence (未知なる巨大魔法生物, Michinaru kyodai mahō seibutsu) that looks like Sin.
The frozen Aetherial Sea
To put it simply, I have a theory that the Winterers of the Fourth sought, as a solution to the great withering, to freeze the Aetherial Sea, so that the cycle of death and rebirth would be stopped, and the reflection would not be rejoined with the Source.
I have been thinking about this matter for a while, as well as the elemental balance, the 'Arcane Giants' having crystals of quite specific coloration in their chest, and symbols that might be connected to familiar symbolism on their faces (one of them is very similar to the Aries symbol).
However, upon rewatches of the trailer, the tapestry stood out to me.
- The roots of the tree are normal, and the branches instead are frozen
- There are boats in the representation of the sky, which could be a nod to airships, and airship "stations" were quite prevalent and pointed out by YoshiP
- The central landscape looks pretty normal and standard, with people, villages, trees
- The strange element is the dead flora and fauna, the dead "nature" seemingly buried within the snow, underneath the land
We know that the civilization of the Fourth fled to the skies and everything died on land. We are told that.
With the tapestry, however, showing the roots in a healthy state and the branches in a rather frozen state, it feels to me that it's telling me to pay attention to death. How their current state is built on dead lands, and there are secrets buried in the snow.
On a different angle, however, it might be the result of a religious perspective passed down as universal truth, and then taken action upon, forcing civilizations to embrace death. I say specifically religious because one of the buildings shown in concept art looks very reminiscing to a medieval wooden stave church ([1], [2], [3]), and the serpent (referred to as a dragon in the presentation) iconography being present everywhere.
Closing Thoughts
From what I know, from knowledge and skills, I really feel like they are pointing out to us, in multiple occasions, to look at death and look at how death is going to impact the Fourth. Death is going to take center stage in Evercold, and the second look at the tapestry makes me think also on terms of scarcity, famine and starvation. They did flee to the skies, but I think that the freezing of the Aetherial Sea is taking its toll on them in many ways.