For what it's worth, I have not found that wolf-whistles and aggressive questioning, like the situation described in the article, are typical of any Wikipedia meetups that I've been to (and I'm an active member of Wikimedia NYC, which is what's being described there, though I was not at the meetup in question). It is
not uncommon for there to be creepiness, especially of the type where someone who makes female attendees uncomfortable isn't spoken to/removed even after complaints (and that's absolutely a problem), but overt aggression of the type described here is foreign to my experiences with not only Wikimedia NYC, but multiple Wikimanias.
If we're going to zero in on what makes meetups uncomfortable for women, I'd say we'd do more user-retention good trying to head off the "random creep attends meetups apparently solely to ogle the women" problem, which is common, rather than the "women are overtly treated like shit when they are giving a public presentation" problem, of which this article is the first I've heard.
-Fluffernutter