I'd go in the opposite direction and interpret the distinction between 'Gygaxian Skilled Play' and 'Skilled Play/MSP' as being somewhat contrived, and at most derived primarily from cultural differences between players-- chiefly in their expectations for where the choices from which they derive problem-solving agency (the marker of 'skill') is located. 'Skilled Play' itself, in my eyes, is simply players being able to solve problems through application of their skillset, whatever that skillset consists of, as a focus of play-- contrasted with play that isn't about problem-solving at all (e.g. games where the emphasis is on telling a story to the extent that problem-solving is in the way of dramatic interactions between characters, and the execution of a story arc.)
I think there is more to it than what you've described here.
@Campbell has noted one aspect of that in his post upthread about 4e: in 4e the space of decision-making and challenge doesn't fundamentally change over the course of play; whereas exactly that sort of change was fundamental to Gygax's conception of the game.
Now as I've already posted in this thread, I happen to think that Gygax's approach breaks down quite a bit once the game starts being published on a mass-basis, so that new players don't get to experience the evolutionary and developmental process themselves but
begin by consuming Gygax et al's fully developed
results of that process. But that is a problem with publishing that TSR never really solved which doesn't undermine the basic point about what it is that constitutes Gygaxian skilled play
From whence does the authority of these people come from on the matter, as opposed to say, me, or those who disagree, have we been cast as an exterior force?
Perhaps even more importantly, is an objective lack of SP the only, or even most likely reason they might abhor a game like Dungeon World? There are probably a lot of other considerations at play.
A fundamental tenet of player-side moves in DW (or AW) is that
if you do it, you do it. And the moves are resolved via a roll that - as a deliberate feature of mechanical design - is kept within certain bounds of probability for its resolution. (4e D&D aspire to the same sort of design, though uses more convoluted methods to get there.)
Straight away that marks out the absence of Gygaxian skilled play. You can't reduce the odds of failure to zero. And partly for that reason, the system provides
no incentive at all to play in such a way as to minimise complications. Rather, it's designed to ensure that complications arise at nearly every turn!
You can see the same point emerging in the "fair trap" thread. In the sort of game where the Gelatinous-Cube-in-a-pit-under-a-Damocles's-block would figure, if the block actually drops and Cube actually sprays everywhere the players are losing. Whereas in a game like DW or for that matter 4e, it is taken as a given that those sorts of fantastic scenes are part-and-parcel of play and the game infrastructure is set up to ensure that they occur.
(I feel I need to emphasis that this is
not a criticism of DW or 4e D&D, either of which I would cheerfully play in preference to serious Gygaxian dungeon-crawling.)