There's absolutely a ton of detrans kink on Tumblr, as you might perhaps expect from the horny trans people website. IME, it's most commonly by and for transmascs - probably a combined effect of "taking T makes you really horny" and the kink-power of (unintended or forced) pregnancy as an identity threat. Many people are quite explicit about it being an eroticization of things that are painful/frightening about their real lives. Search the rot13 of "snxrobl" or "snxrtvey" if you want to find it.
Yeah, the “misgender me with your dick” thing. I’m kind of unsure how to take that sometimes because recalling the old Craigslist Casual Encounters, “treat me like a girl and give me your str8 load” (alt. “breed me”) was a pretty common fantasy scenario for cis gay men too