It is needlessly essentialist.
There's a difference between an essentialist gender outlook, where gender is an essential aspect of people with a certain biological configuration, and an objective gender outlook, where gender is an objectively observable configuration of human minds.
Specifically, the difference is that after the Great Feminist Cultural Revolution, gender won't objectively exist. It will have been erased from institutions, individuals, and cultures (by "after", we mean "hundreds of years after").
Gender is like any other socially instilled bias, except that it tends to run much deeper (gender socialization starts at birth; religious socialization starts later, and isn't connected to one's anatomy at all). As such, it does objectively exist, and you can't handwave it away.
As far as I can tell, this is a definitional dispute. There are many traits that females express in modern society. I take essentialist theory to be saying that all of these traits are based in sex, not in gender.
As you say, this is wrong - lots of these traits are gender and would disappear if feminist social engineering succeeded. Only those traits actually based on sex would remain
I was criticizing the position you expressed that men have literally nothing to say about the dividing line between female gender and female sex. For example, a man can say "Getting pregnant is an expression of sex, not gender" or "Wearing dresses is an expression of gender, not sex."
Upon reading Eliezer's possible gender dystopias ([catgirls](http://lesswrong.com/lw/xt/interpersonal_entanglement/), and [verthandi](http://lesswrong.com/lw/xu/failed_utopia_42/) and the other LW comments and posts on the subject of future gender relations, I came to a rather different conclusion than the ones I've seen espoused here. After searching around the internet a bit, I discovered that my ideas tend to fall under the general category of "postgenderism", and I am wondering what my fellow LessWrongians think of it.
This can generally be broken down to the following claims:
EDIT- Due to some really insightful comments;
I replaced men being prone to aggression as a negative, with men being prone to suicide.
I made the verbiage a little more explicit that no one would be *forced* to change, but would seek out the changes that transhumanism would have available.