I doubt that very much. People can always be wilder than fiction. I'm not aware of any sci-fi that predated gender fluidity, for instance.
Ursula Le Guin's The Left Hand of Darkness (1964) had gender fluidity, before it was called that. It was central to the story.
> Robert Silverberg's Son of Man (1971), whose protagonist is transposed into the Far Future and there experiences a wide range of ways of being human, including being female...
See https://sf-encyclopedia.com/entry/transgender_sf for many entries before 1990, or even 1900.