Might help also to describe what you think feminism is, since it’s one of those terms that is overloaded.
I once had a physical therapist tell me she wasn’t a feminist because she thought women couldn’t be as physically capable as men when serving as soldiers, and seemed to believe feminism requires treating women exactly like men.
I told her I was a feminist because I believe in equal rights for men and women, an idea she did not seem so opposed to.
This doesn’t really align with my experience of gender. Which is to say, I think what you’re describing here is a large part of gender, but it doesn’t encapsulate it completely. I’m trans, yet I’ve never had a strong sense of “femininity” or “masculinity”. I don’t really “get” gender expression, except in so far as it’s a tool to have people see my gender. I certainly don’t have a sense of it being tied to my internal experience of my gender. Yet for all of that, I’ve always had a strong sense of gender.
In a genderless world, I don’t think we would all be genderless in the strict sense of the term, but more, our internal experiences of gender would be assumed to be unique, and as such, not really something that can be grouped in to labels and compared to other folks. In this world, what we now call gender expression, would just be self expression.