One motive for preferring my framing is that it empowers a designer to say "given cue X has result on play Y, I can make choices about that cue with consequences for Y". A designer has more direct control over the cues they incorporate into their design than over any given eventual player. Emphasizing that link is worthwhile.
I don't know what you think is obscured, in my characterisation, of the connection between
design and
play outcomes. These are generalisations about the effects of cues. They don't require imputing those outcomes to the cues as properties of the cues themselves.
There is actually a well-known paper relevant to this point, in the field of political and social philosophy: John Rawls, "Two Concepts of Rules". Rawls' basic point in that paper is that (i) we may have reason to want a social institution that will achieve outcome X, and (ii) we may have reason to
avoid making X, or the aiming at X, or the attainment of X, itself a component of the social institution in question.
A simple example: we may wish to increase safe driving and reduce the incidence of dangerous driving, by (i) adopting a road safety law; but (ii) we may best achieve that goal not by adopting a law that refers to safety or danger, but rather that proscribes some particular sorts of behaviour (eg driving fast than N kph, or with more than such-and-such an amount of alcohol in one's system).
Likewise, the RPG designer who wants to engender a certain sort of conversation (a cool one; one with rising action and crisis; etc) will want rules that do that, but it may or may not make sense for the rules to talk about those things (the AW rules don't) and for the presentation of the rules to exhibit those features themselves (again, the AW rules don't - they are nicely and colourfully written, but they don't have rising action).
I want to be able to say something like "When the game designer makes changes to the cues they incorporate into their text, that has the foreseeable consequence of changing the way their game normally plays at table."
Well, the way to say that is to say it. It seems pretty straightforwardly true in some cases of changing the cues - but not in all cases, obviously, as there is clearly a lot of conjecture and hope in RPG design.
There is no relationship between pointing out that aspect of the RPG design endeavour, and other things like whether or not RPGing involves rehearsal, or typically permits significant editing of the shared fiction.
My claim is that it is distinctive of TTRPG play that the game text can be prescriptive without scripting the story precisely (as it is in other media).
This isn't distinctive of RPGing. It applies to any story-telling game, doesn't it? (The one I'm familiar with is A Penny For My Thoughts; I'm sure there are others. Maybe Rory's Story Cubes counts too? I've certainly seen children use the cubes to play a storytelling game, and the procedures they use could be written down if anyone wanted to.)