"I'm discussing Ursula K. Le Guin, who, and despite advanced age, is big on Transgenderism..."

Interesting that you consider Ursula 'big' on transgenderism. I hark back to the 60s SF when she wrote 'The left hand of darkness':

https://www.goodreads.com/book/show/18423.The_Left_Hand_of_Darkness

From memory, she has always been on the left, which, at the time was unusual, coming from an US author.
Just because she wrote this speculative book, does that qualify her as being big on trans .. unless there is evidence that later she has pushed this issue. Has she?

And from Ken: I read a lot of science & fantasy fiction and certainly the gender bender element is "inclusive" growth Industry stuff. Imo this does not have a connection to Ursula's writing per se imo .. that inclusive industry is more in the 90s or whatever. I challenge you to prove me wrong : )