"Multifaceted gender expressions and LGBTQ+ rights are constantly negotiated and contested. While in recent decades, gender definitions and LGBTQ+ rights have expanded in many parts of the world, Wakashu illustrate how quickly more open and fluid understandings of gender and sex can be repressed and erased."
And the other idea you're conflating is that (which I think the article dispels) is that feudal Japan consider youth to be tied to age. For all we know, it might be a concept unfamiliar to us westerners that got projected onto "youth" to make the article approachable to Western audiences.
"In the United States, as late as the 1880s most states set the minimum age [of consent] at ten to twelve (in Delaware, it was seven in 1895)."
Now to reply the post, just because 100 years ago was legal it doesn't mean it was normal or moral. The post is more enforcing in the same direction - legal in ancient Japan, legal in modern Delaware. I am waiting for more examples of legal pedophilia.
This article is not about gender, is about normalizing pedophilia.