they generally just go with what they prefer in the moment along lines that don’t match the gender binary

Nope. Lego did a large behavioural study on this because this was their assumption, they thought they were doing completely gender-neutral stuff, but even controlling for parents's biases their stuff wasn't gender-neutral when it came to actually be interesting to kids. I'm talking about stuff like the city series, here: A street, bunch of houses, bunch of minifigs. Figures that the girls by and large where looking at the inside of the buildings, finding them empty, and lost interest while boys where seeing the streets, found ample of detail and also a car to drive around, and created stories. There are, of course, as always exceptions to the binary but the overall trend was undeniable.

That (and the insistence of US stores on not having gender-neutral isles and putting Lego in the boy's section) made them create the Friends series: Detailed house interiors, larger, more detailed minifigs. The pink is for the stores and parents, the interiors for the girls, the build-what-you-want flexibility for the humans.

Generally speaking, I think that difference feminism has been discarded prematurely. Sure, none of the normative BS that many of its proponents espoused should ever see the light of day, but denying difference is harmful in its own way, and the reason is the inevitability of essentialising: If you say "there is no difference at all between men and women" you're bound to essentialise everyone towards your own gender. And it's way better to be essentialised as an apple when you're an apple than it is to be essentialised as a pear.