I think you're right about the socially adept overhugging situations. Nevertheless, I don't think the non-hugging-without-asking advice is helpful to the intended audience.
For one thing, this socially-adept over-hugger, for all his flaws, is still much preferable and beneficial to the group than the archetypal, socially-inept creep under discussion. So, while the overhugger might be strictly better for the group to the follow the hugging advice, I would still say the most important thing (the low-hanging fruit here) is to teach the creep the things that the overhugger is doing right, not to tell him to avoid the things the overhugger is doing wrong.
Like I've tried to demonstrate here, it's hard to form a model of the things you need to do in a group setting when a) you don't know how to act, and b) all advice you get is in the negative. If it does anything, the negative advice just reinforces a mental model that says, "to be on the safe side, don't even talk to anyone because you might hit one of the prohibited things", which is not a step forward. And if my own experience is any guide, it just blends into the same old message of, "your desires are bad, how dare you act on them" -- not a healthy mentality to encourage in the target audience, who probably already assimilated this message early on.
One of the lessons highlighted in the thread "Less Wrong NYC: Case Study of a Successful Rationalist Chapter" is Gender ratio matters.
There have recently been a number of articles addressing one social skills issue that might be affecting this, from the perspective of a geeky/sciencefiction community with similar attributes to LessWrong, and I want to link to these, not just so the people potentially causing problems get to read them, but also so everyone else knows the resource is there and has a name for the problem, which may facilitate wider discussion and make it easier for others to know when to point towards the resources those who would benefit by them.
However before I do, in the light of RedRobot's comment in the "Of Gender and Rationality" thread, I'd like to echo a sentiment from one of the articles, that people exhibiting this behaviour may be of any gender and may victimise upon any gender. And so, while it may be correlated with a particular gender, it is the behaviour that should be focused upon, and turning this thread into bashing of one gender (or defensiveness against perceived bashing) would be unhelpful.
Ok, disclaimers out of the way, here are the links:
Some of those raise deeper issues about rape culture and audience as enabler, but the TLDR summary is:
EDITED TO ADD:
Despite the way some of the links are framed as being addressed to creepers, this post is aimed at least as much at the community as a whole, intended to trigger a discussion on how the community should best go about handling such a problem once identified, with the TLDR being "set of restraints to place on someone who is burning the commons", rather that a complete description that guarantees that anyone who doesn't meet it isn't creepy. (Thank you to jsteinhardt for clearly verbalising the misinterpretation - for discussion see his reply to this post)