"Ah yes, trans people are oppressed because of people like me saying that misgendering is transphobic… you’re such a “rationalist” you have managed to go beyond the bounds of reason entirely! Incredible!"
You said oppressed.
That aside. The process of birth is more of a hormone 'whole body' thing. Even if it were the case that getting pregnant and giving birth didn't cause any dysphoria - that'd likely be the result of careful therapeutic input. I'd hazard a guess it'd be some fairly intense CBT. And guess what... if you can overcome that. You can overcome pretty much everything else.
Being misgendered might qualify as mistreatment if done intentionally, but I don't think that's the case here. Midwives have a lot of shit going on and 99.9% of the time the vagina they're seeing belongs to a woman.
So yes, I suppose at an outside definition I could see myself agreeing this guy was accidentally mistreated.... but if you think the best way to win people to the cause of liberalism is to berate them for every mistake, you're going to be setting the trans-community back a lot longer than I am.