Will have more thoughts about Left Hand Of Darkness in and of itself because it deserves it but part of the reason I read it was knowing how much my beloved Radch books were in conversation with it and ohhhhhhh it's so tasty.
I know Le Guin changed her mind about the pronouns in TLHOD later in life, but the book that exists is the book that exists. It's both a very interesting snapshot of the time it was written, where "universal" he/him was in vogue, and interesting to consider from an in-universe perspective; Genly is writing and translating in a language/milieu that Gethian androgyny doesn't readily fit into.
It shows, I think, how quickly the fiction of masculine pronouns as universal, as "unmarked," falls apart. Genly says, "man I must say, having said he and his," when English (and presumably his own language) has the perfectly serviceable gender-neutral term "person." Even if keeping the pronouns, he could have made some effort at neutrality by using person, sibling, parent, and other neutral words where appropriate. But no. It's always man, brother, father (except when talking about a birthing parent, in which case it's "mother".) He's so entrenched in the gender binary and male-as-default that even though there's only one actual self-identified man in the book it can still feel, reading it, like all those other sci-fi books that have entirely male casts and forget that women exist. As a reader you know it isn't, but it can take active effort to read against the language being used and remember that everyone except Genly is actually genderless.
Which is why I like what Ann Leckie does so much. Yes, we should have more stories that use they/them and neopronouns for agender/non-binary characters and societies, but with the long history of masculine-as-default language it's really cool to see a series that flips that on its head. What happens if we take a pronoun (she/her) and gender that everyone agrees is marked and use that as the universal? How does that affect the way you read the book and the characters? (Do you default to thinking of them all as women or does the very marked-ness of the choice help you to remember that the gender binary shouldn't apply?)
And of course, how different does it feel to have the narrator writing from within the alien-to-the-reader culture instead of from outside? To have the pronoun choice be something imposed by the invisible "translator" instead of a choice the narrator is actively making? Genly uses "he" because he's from a binary society and too afraid to use anything else. Breq uses the neutral unmarked Radchaai third-person pronoun, but within the fiction of the book this has been translated as "she".
The Radch books are extremely concerned with translation and linguistic differences, and the unusual pronoun choice (some might even argue "incorrect") does a lot to underscore the arbitrary nature of language and the way in which translation is not and cannot be a neutral activity; it is always a transformation, it is always shaped by cultural forces, even and especially when those forces are so normalized as to appear invisible.