Slight clarification that doesn't alter anything about your reply: in the "get coffee" scenario I meant it as "go fetch coffee for the meeting". That's a stereotyped role in which women were assumed to be mothers/caretakers to the office in addition to all of their other duties, but which men would think was their primary duty.

He could ask somebody to get coffee without intending to bring up a whole history of chauvinism that you weren't even aware of, but it's also kinda his fault for not thinking it through.

That's just to clarify what I said above, not really a reply to any of the points you bring up. You're right that in the end this is inherently fuzzy. But I do think it's useful for everybody to say "I'm going to do more than just the bare justifiable minimum, because there are real issues out there, deliberate and otherwise."

That's not an injunction; it couldn't be. But it's something to think about, and the people who say "I'm not going to think about it because it's not my problem" are almost certainly the problem.