It's up to each viewer to interpret.
I see strong religious themes, in the context of anthropology instead of spirituality. We see the beginning of organized group structures which started after the last of us is gone. (tee hee)
It's using an overload of religious references and metaphors. (including "clip her wings" which is about competitive survival against rival groups, punishment, control, power, order, and justified with religious and racist meaning). How the group structure and power influence the repression of innate empathy.
All of this will have counter-themes and struggles in the main characters. Which is also in the trailer.
I definitely noticed some of the religious language. Some other group is referred to as demons, but I can't remember who or which character said it. The woman with the knife who is threatening to disembowel the other woman that's being hung also says something about sin with reference to her stomach, but I can't remember what.
You see competing factions of people, but there's no real hints at their motives, or what's led to the violence. The people being hung and disemboweled seem to be viewed as traitors to their group. There seems to be some kind of religious fanaticism, maybe blaming the sins of humanity for the monsters in the world. All in all, it seems like typical stuff for this type of story, especially the current trends in zombie/infected stories. It's kind of the typical story arch in most of this stuff - especially the walking dead which just keeps repeating variations of the same story arch over and over.
You've obviously taken a lot more out of the trailer than I have, maybe because I didn't play the original game. But I still don't see the purpose of having this content in a marketing trailer, without any context at all. I feel more like they were trying to market how brutal the game is going to be, as a selling point.