Calling Jenner "he" versus "she" has important implications for the speaker's understanding of gender identity.Does calling Jenner "he" versus "she" tell us something about the speaker's understanding of gender identity? It might, or it might not. Myself, I would never address Caitlyn Jenner in anything other than the way she wants to be addressed, but that doesn't have anything to do with my understanding of gender identity. It just has to do with my understanding of manners. If you're introduced to somebody at a party and the person says "Call me Caitlyn," wouldn't it be quite rude of you not to do that? ("Hold on now! I know who you really are, and I'm going to call you...Bruce!") What kind of an asshole would do something like that?
Well, this guy, for one, although I did see that he later apologized.
Much of Twitter might not exist if more people had had better upbringing. I don't think anybody in my family would ever behave the way that guy did, because our mother raised us better than that. She might or might not have celebrated sex-change operations altogether (I never asked her about it), but as a well raised Southerner, she probably would have shaken Caitlyn Jenner's hand at a party and said "I'm pleased to meet you, Caitlyn."
Years ago when I was studying at the Mathematical Institute in Oxford, there was a male researcher who dressed in women's clothes. Or at any rate, I judged it likely that he was male, and people referred to him by a masculine name. I also judged it likely that he was wearing women's clothes, however questionable may have been his habit of wearing thick white socks with open-toed pumps. Anyway, nobody cared. Almost a hundred percent of all mental activity occuring at the Institute was directed toward proving theorems. Maybe Twitter is what it is in part because the effort required to send a Tweet is too small to interfere with the doing of more important things.