I can see how it can be extraordinarily useful...if you buy into the framework. It's especially useful if you want to run a "story-now" game, because it does a lot of work to zero-in on that particular playstyle. But it does strike me as a closed system that does not admit overlap between its categories (at least in the way that I've seen articulated) and that becomes self-referential. I mentioned upthread one thing I liked about that "six cultures of play" article was that it was open: it admitted overlap between the styles, showed how they influenced each other (positively and negatively) and left itself open to there being a 7th or 8th culture of play. As someone else phrased it, descriptive rather than prescriptive.
I'm sorry, but you seem to have a large mistake in your assumptions. There's nothing in my "framework" that precludes other things from adding additional distinctions, and I happen to really like the Cultures of Gaming article -- it provides distinct and clear difference in the objectives and means of play for the categories. There's not a single thing I've said or advanced that precludes this, or precludes other distinctions. The topic of the thread is authorities in play, and that's a primary point of distinction between Story Now and many other cultures of play form that article. In fact, of all of them, it's really just Story Now and Nordic LARP that deviate from the authority over backstory and framing that's common to the others. So, in this thread, on this topic, I, and others, have been discussing from that point of view. I have repeated offered discussion on the other types of play and how they stack up and differ from each other. But one thing common to Classic, Trad, Neotrad, and OSR play is the framing by backstory-first principles. And, if you look at how games developed, this makes quite a lot of sense.
So, yeah, it seems you're arguing the one point about how backstory-first differs from situation-first play and expanding that further than anyone advocating it has pushed it.
What I have already said? Taking aspects of one game and letting it influence another. Thinking about "failing forward," or "thinking offscreen," and adapting it to a 5e context. Or, let's say you adapted the mechanics around "load" from BitD to 5e. That seems doable (and in fact I think some classes have features where they can create certain kinds of items). Would it serve the same function in a typical 5e game? No, but it would change one facet of the game in ways that seem meaningfully different that default 5e play (in which you write down your equipment beforehand).
Failing forward is something that's been around for a long time, and has previously featured in D&D before DW was even a thing (ie, 4e, although it goes back a bit into some discussions around 3e as well). Thinking offscreen is the primary mode of GM play in D&D, so I don't see how that's being borrowed from DW. Heck, we're told all the time about GM solo play being used to bring the setting to life in living world sandboxes. This didn't come from DW, as I saw (and did) that back in the late 80's, and certainly all through the 90's and aughts with 1e, 2e, and 3e play.
No, you haven't actually put forth a single example of pulling something unique to DW play into 5e. I think it's because you don't know what DW play actually looks like, so all you can do is grasp at terms that you imagine to be a way and suggest that this is DW leaking into 5e. It's not.
When I first made the shift over to thinking how you have to to play/run Blades in the Dark (my first Story Now game), I loved it and thought, "self, you could totally pull this naughty word into 5e and make it better!" So, I tried. I am not a slouch or an idiot, but I rapidly found I couldn't make it work without just fiating all kinds of things. 5e lacked the necessary framework to make sense of the core play of Blades. Or any PbtA game, as I went on to learn. It doesn't really work, at all, because system matters and these are different systems. That's not just a mechanics thing, although that's part of it, but 5e and Blades have different goals of play. They're not even really pointed in the same direction, much less work the same ways! So, I quickly abandoned these attempts. Instead, I play 5e for 5e, for what that system does and how it does it. If I want a different thing, I look for a system that supports it. I love 5e, but I have no need to try to make it do anything and everything, nor is my identity so wrapped up as a 5e supporter that I can't admit it's not the perfect vehicle for anything, if just for want of the right house rules.
So, the arguments you're making really smell like a need to defend 5e from a perceived attack -- to ensure that 5e comes out on top and wins the war and it the thing. Okay, I don't know why that's important, but it's definitely hampering the ability to actually analyze what's going on in play because there's a need for 5e to not show any lack. Personally, my 5e has gotten much better now that I lean into the system for what it is and know where the potholes are so I can steer around them. My Blades has gotten better for the same reasons -- knowing the potholes of a system, and where the road maintenance ends, is super duper helpful. But, if you're investing in 5e as a matter of identity, this will be a hard thing to do.