There's no progression in the story. They keep going from one area to another, encountering other humans whom they have to fight (and eventually massacre). And all the main characters go through "adapting" to this new world, learning to harden themselves against the brutality, rediscovering their will to live, to continue on, in the face of this bleakness.
Then they kill off some regulars and bring on new ones, rinse and repeat.
The formula works because they do a great job of vilifying new enemies so the cathartic and inevitable vanquishing of these villains is crowd pleasing.
Yeah they can't have answers from either show because they don't need to risk the franchise. But the new show is basically going to follow the same trajectory, as people "adapt" to the brutality of the post-apocalypse, with the tried and trued cynical killing off of regular cast members periodically. So the new cast will figure out how to kill the walkers, learn to survive, get over the PTSD, ratchet up their brutality, then learn the most dangerous things in this world are other humans and then have the same kind of battles.
Since they're satisfied with TWD being a survivalist morality tale with a set of sympathetic characters battling one villainous set of characters after another, why wouldn't FTWD eventually reach a similar state?