I would normally be in favor of more pronouns, but I can't think of any instance in which a Sim's pronouns are actually used in-game? I don't have DLC for Sims 4, but in the base game as well as Sims 1, 2, & 3, the Sim's name was always used, not their pronouns (IIRC ofc)
Also it's true that not every language is capable of gender neutral pronouns. Chinese for example, it's always gender-neutral when spoken ("tā") but there isn't a gender-neutral way to write it. 他,她,它 = he, she, it; all pronounced the same.
Like German, there are a few new variants, but none are "official" and it depends on the user. I wonder, in this case, what would be used?