Actually the idea comes from feminism from literally the 1980s-1990s, from well respected feminist theorists. But thank you for illustrating how tied together the rights and oppression of cis women and trans people are.

Read "Bodies that matter, on the discursive limits of Sex" from Judith Butler.

Also understand the definition of a social construct. Social construct doesn't mean fake, it means falling into a classification scheme that is socially manufactured. Something that is 12 inches long isn't "fake" in its 12 inch longness because measuremenr systems are socially constructed, it just means that it can become 10 inches long or 14 inches long if the length of an inch is redefined. And you would be wrong if you told someone that no, it is incorrect to call it 30.48 centimeters long. People can apply different classification schemes/social constructs to the same physical object and still be correct. They could also call it ten blagards long and be internally consistent within their classification scheme, but that wouldn't have utility within a social context because the meaning of blagard hasn't been socially constructed.

An inch isn't some innate objective truth, it is a common standard.

The sex binary is a commonly applied standard, but it is arbitrary and harmful (see how women are treated rooted in myths around sex, the prolific mutilation of intersex infants, and the "trans panic defense"). If inches being the length they were started resulting in engineering failures that killed people we would change how we measure things.

Well, it does and we don't, but you get the point.