Actually, @Ragnarok, based on what you said earlier about Czech, is it the case that if there were the possibility of our PCs being misgendered by NPCs, that might mean different dialogue options for different localisations?
For example, in English most NPCs could make incorrect assumptions about our gender and we’d never know, so not have a reason to correct them. But if what I understand about Finnish, for example, is right, even in some cases where in English it would be clear from the pronouns used the NPC had your gender wrong so you might want to correct them, that option wouldn’t be required or appropriate as the pronouns would be the same. But from what you said about Czech, it might be obvious much more often or earlier that the NPC was in error, and therefore there would need to be more dialogue options for correcting them. Is that right? If so, I can see that would create more localisation challenges, and might be another driver for just having NPCs use the gender the player specifies rather than trying to do anything more complex.
"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"
