Remember when you were saying you didn't need extensive knowledge of every game ever to analyse aspects of them?
Narrativism is literally just playing make believe where each player is a little DM. Literally any game can have that sit ontop of it. I could be playing candy land and sit there and just make up stories and narratives while I did it.
In so far as anyone here has been able to explicate, narrativism interfaces not at all with mechanical rules. If people can sit around and just collaboratively tell a story and play make believe, they can slap that ontop of any other activity.
I've barely been involved in this thread for awhile (and even then, not much) and I'm just doing a really quick look at what has transpired.
Wow.
This is one of the more (confidently asserted) incorrect takes on Narrativism that I've seen. Your mental model for how these games work is not connected to the reality of the play of these games. Every sentence you have written above is incorrect. If you're interested in this subject at all and interested in having an updated mental model of these games that more resembles what is happening under the hood and what transpires at the table, I would look a lot further into the subject and I would actually play a nice cross-section of the games in question (actually play them though...not sub in traditional models/conceptions of play and ignore the principles and procedures of the systems).
* Narrativism isn't just make believe where every player is a little DM. The roles of GM and player are absolutely and vitally different. In fact, there is a case to be made that, although Narrativist GMs are deeply constrained in certain ways that traditional GMs are not, the authority over situation-framing that Narrativist GMs have absolutely surpasses that of traditional GMs.
* System and mechanical rules matter profoundly to these games (not just to distinguish them from alternative models of play but to distinguish them from each other within the category of Narrativism). Dovetailing with the above bullet-point regarding significant GM authority over situation-framing, the bulk of these systems have mechanical architecture that imposes conditions on PCs that most traditional players find seriously troubling.
* The procedures and experience of play is absolutely not collaboratively telling a story, "conch-passing", or a "writers room dynamic." Players build protagonists with motivations. GMs play rules & principally-constrained adversity/antagonism to those protagonists and their motivations. In the middle of it, characters rise, fall, change, retire (for whatever quality of "retire" the game in question supposes). Rinse & repeat until all matters are settled.
* To put the above three bullet points together, there is a GM meta + player meta = general orientation to play dynamic in these games that would be cast as "adversarial GMing" by GMs/players of a traditional mindset; 100 % (I've seen it live on multiple occasions). GMs must relentlessly attack PCs where it hurts. All the time. Put them in spots. Push their buttons. Buttons that are cited by players (at PC build stage) and by the design of the game generally as "meant to be pushed." In fact, if the GM lets up or doesn't attack, they aren't doing their job. If you're a player who doesn't have their head around this concept, it will break your brain and you'll wind up having a bad time. If you can get your head around it and enjoy playing to find out who this character is while aggressively advocating for them (the same way as happens in real life...we don't know who we are or who we'll end up being...but we sure as hell will advocate for ourself in the course of finding out), you'll have a great time.
I really think a lot of people have Story Now ("Narrativism") play mashed together with NeoTrad/Original Character Power Fantasy/Flex kind of play in their minds. This harkens back to my problem with the "Storygame" taxonomy erroneously capturing both of these orientations to play. They are very_very_very different play agendas/cultures of play/system designs and using Storygame is a contributor to this confusion (imo).
Story Now games are the opposite of Power Fantasy. They have no ROFLSTOMP Flex moments or character arcs that the GM is responsible for curating play towards as is fundamental to NeoTrad/OC games. There is no "players bring a conception of character to play and the GM must ensure those story beats/character arcs are realized in the course of play" in Story Now games. Its actually the inverse of that in both ways.