I got the additional impression that there are bounds to how freely the reader can interpret the narrative. Thus freed from endless mental contortion to make the argument work, the reader can assume that they are not too ignorant to understand the wit of the author but actually able to judge them as lacking. - The author has not made themself beyond reproach by presenting an irrefutable argument.
I hadn't thought in terms of hostile argument... you see this in verbal argument sometimes, where a person rambles or says vaguely contradicting things to prevent themselves from alienating their fan base.
Ambiguity lets people who endorse you to contort their interpretation into something they like.
So I think their advocating for specificity makes sense, it helps ensure that the argument is about some _thing_ and you're not engaging with some unknown meta game that lives outside the argument itself.
Less about falsifiable or correct and "does this compile".
More "can I easily grok what this function is trying to do even if it isn't compiling".
I see this term as an attempt to define a precursor to "Cogent" or maybe it's an attempt to give "Cogent" a more formalized definition.