This person is so full of shit it's coming out their ears.
A bisexual, non-asexual person who has become tumblr famous for extremely questionable history posts about LGBT history, mostly about how asexuals have been part of “the community” from the beginning.
Their most famous post is about the entirely fictional “spinster movement,” which was supposedly a widespread movement that lasted from the 1880s to the 1930s of women who didn't want to have sex, who would mostly have been considered asexual in modern terminology. As of March 27, 2016, that post has 35,907 notes.
This post was fabricated out of whole cloth from some much milder assertions in an actual history post. The author whose work was distorted complained here: as of March 27, 2016, their post only has 21 notes.
Autismserenity also has a habit of fishing through Google Books for late 19th-early 20th century mentions of the word “asexual,” using it to mean the same thing as the identity term coined in 2001, quote mining and distorting what was said, and drawing very questionable conclusions from this. (FFA discussion here). They also assert that 20 years ago, asexuals were “part of the bi community,” with no source given (FFA discussion here).
A nonnie remarked that Autismserenity's “history” work is an example of tumblr's power to spread misinformation without any easy way to correct it.
Autismserenity can be thought of as an LGBT history equivalent of Girljanitor/Medievalpoc - making up assertions out of whole cloth, distorting facts, applying modern categories to historical people and sources when they don't really apply, and drawing extremely questionable lines about who counts as part of an oppressed identity and who does not.