Hi! I'm pretty new to these forums, and to the game itself, really. But I'm also a lore nut, and have been screencapping nearly all the conversations that appeal to me lorewise when npcs talk to my character. Since the Sylphs particularly interested me, I'll pipe up here.

It wasn't until later in the quests that Sylphs spoke with pronouns at all (as opposed to 'these ones', 'walking one', etc.), but when they did, 'him' and 'he', both in the quest text and by what the npcs said, lined up with Sylph names that ended in 'xio'. Specifically, the ones mentioned were Frixio (the elder) and Claxio, both ending and 'xio' and both having been spoken of by other Sylphs with 'he' and 'him' pronouns. Later, Noraxia is referred to as 'her' (by Minfilia), and consequently has a -xia suffix to her name.

While these are only a few cases, based on that, I'm willing to bet that the minion text, and the quote are both true. (Screens to be posted at request)