Going to assume this phrasing is an awkward translation, but we can see how this works out in tolerant nations with conscription like Thailand. Typically, trans women who are already on a medical pathway are medically excluded from military service. This is less an affirmation of who they are by the military and more of a frank admission that their current state could never be made combat-ready. It's likely that even if SHTF, this would remain the status quo, because it's difficult to imagine draft resisters taking estrogen simply to avoid service. Even if treatment is largely done via informed consent, medical exclusion would likely require blood levels be in a certain range, or certain surgeries performed.

As far as I know as long as the change was made outside of an ongoing conflict and it's reasonable to assume it wasn't done to evade a potential one, it would actually protect you from being sent to your death

IDK about legal situation, but I know people who transitioned in both directions and they tell me that the hormones they take do make a big difference to strength and resiliance.

Saved, can freely enjoy cocktails on the beach.

The registered gender is the one that counts.