That's still only conjecture though, even if it does make sense.
Due to English and Japanese working differently on the pronoun side it's sort of justified.
Gems refer to themselves with gendered pronouns in Japanese, because those exist there, but in English there's distinction only in third person. Referring to oneself is not the same as referring to someone else, so this isn't a case where the gender in pronouns is directly transferable, because the meaning would change.
Is there something lost in translation? Obviously, but gender neutral language fits in a way because it avoids causing associations of supposed gender that may not have been the intent of the creator. "That gem" or name are somewhat clunky at times, but it's understandable.
Same could have been achieved with the use of generic he, but this is simply falling out of common, or even accepted, use.
Singular they isn't a thoroughly accepted form either, mind, but it is replacing generic he as the choice for indeterminate or unknown gender. Prescriptive grammar is usually always a little late anyway on following how language actually develops and changes.