I do now attempt to use the single-word non-gendered collective nouns in speech myself for the reasons I gave, and I think it’s a good idea to do so.
To discuss the edits to Dahl’s work: I would argue that for these ‘Xs and Ys’ examples he was probably just using the popular idioms of the time rather than choosing them to convey a specific meaning as you say. That would certainly be what I would’ve done, without much consideration, 20 years ago!
But that’s obviously not the case for all the edits that are reportedly being made.
The edits in aggregate do make me uneasy. I’m not sure how I’d feel if they were more limited.
I hate to be the guy that cries “1984,” but do we really have to completely neuter our language to avoid every imagined offense? Are there people out there who’s egos are so fragile that they can’t handle “gentlemen” coming after “ladies?”