I honestly felt like it got better as the post went on. The middle was the most boring part, though, even as someone who enjoted it.
I'll agree that it's more than a little redundant, especially when I understood the point he was getting at in the first part. But how much of that is the fault of his writing here and how much of it is the fault of the fact that he's written about the issue before? And, more importantly, if you were to hand this article to someone who knows nothing about Yudkowsky or Less Wrong, would that extra length help them? I'd argue that a lot of the article's length comes from trying to avoid some of his most common problems - instead of referencing a post where he'd said something before, he would explain the concept from the ground up using a different metaphor. (which is good for those of us who don't want to scrape through old Facebook rants)
Either way, in its current form it is definitely not out of place for rhetoric, and more than enough for Less Wrong.
I'm not the biggest fan of how large the recommended reading is. I understand the incentive to drive people to read the sequences, but the images and text are the single largest presence on the landing page. I could understand if it was at the bottom, or perhaps in a non-existent sidebar, but as it stands, they feel a little imposing. The font is pretty good, and the interface is clean, but I'm afraid it might be a little too clean - there aren't very many colors on the page to hold your attention. Also, it might be a good idea to add the functions for italicizing and embolding above the comment box, in order to prevent people from trying to use reddit markup. (or just add in-built support for the markup to begin with)
Is there any plan to add a feature that allows citations in a post? It's not that important, in the grand scheme of things, but seeing as the website is oriented towards encouraging comprehensive reading it might be useful. Additionally, I agree with some of the other comments here that the general website speed is slow. I made quite a few spelling errors in the first draft of this post due to lag. I have yet to try using the site on anything other than my crappy chromebook, which may be the issue, but even then, that's a huge blow to accessibility.
Other than that, I can't think of much. It's definitely an excellent effort, so far.
It's not really necessary for Japan to be a hub of avant-garde feminism in order for a particular piece of art from Japan to be sexually liberated. Realistically, it's more that any country with a strong focus on cultural exports like animation will eventually, through sheer volume and luck, manage to create something progressive. Look at all of the corporate media in the United States that manages to smuggle in anti-capitalist themes. It's more of an indication of artists as a whole being progressive, rather than the people who hire them.
I think you're right in saying that feminism isn't always correlated with a blanket anything-goes sexual liberation, and that it's more of a trade-off, but I'd argue it's a trade-off which allows for other freedoms to be expressed in a sort of knock-on effect. A feminist society might have a taboo against marital rape and molestation where a traditional society would not, but the effect of that taboo is that people feel more comfortable expressing themselves at their own pace. That's assuming, of course, that there is a consistent feminist position on sexual liberation, which isn't always true.
It's worth keeping in mind that every popular movement has its stuffy closed-minded members. What you see as a motte-and-bailey I see as two (or more!) clearly different factions, stratified by age and political alignment, which cooperate occasionally to promote uncontroversial women's rights like access to abortion and maternity leave etc. The divide between sex negative feminism (all pornography is exploitation of women) and sex positive feminism runs pretty deep, and I think is more a symptom of feminism's long history. We're talking about an umbrella that contains all four waves of feminism, some of which were built on some pretty radically different principles. The writings left behind by the suffragettes didn't just go away because the fourth-wave feminists are here, and there are entire swaths of people who echo those writings because they're more palatable than queer theory and postgenderism and so on.
As for the persistence of gender roles, I think option 1 is the most likely. Less that it's a stable equilibrium now, and more that there's just a ton of cultural inertia. Zoomers like me were still raised with gendered toys and clothes, however diluted they are from my parent's generation, and we're only barely old enough to vote. A fraction of us will pass those preconceptions on to the next generation, who will then pass a fraction of a fraction of those preconceptions on to the generation after that. It's worth mentioning that fourth-wave feminism is hilariously new. Newer than rationalism is! It will take a while to see where those ideas lead us.
There might be a dash of option 3 as well, but working in the opposite direction - there seems to be a massive unmet demand for gender nonconformity. Think of all of the women looking for kind, sensitive guys. Or men who like tomboys. The people who most strongly using traditional gender roles as a signal are trans-women and trans-men, who feel compelled to overcompensate, and their existence is something the classic conception of gender doesn't permit. If we're being naturally pulled in any direction, it's that.