I think this is a pretty good definition of what Narrative gaming means to most people and almost everyone whose first experience with it was with PbtA games. It is recognizable and a lot of games fit into this category. It's also quite different from the default experience of a game like D&D that, again, most people are going to be familiar with. I think it's instructive and useful to talk about game design, and it's clearly the intention of Daggerheat.
The problem is that it isn't the same definition of Narrativism, which a lot of older gamers are familiar with. That definition has very few games that apply to it, and they tend to be very niche games. If we're going to say that Narrative games aren't what they claim because they don't fit the definition from a debate on Usenet before most new 5E gamers were even born, what are we saying?