It's so low-key that they used two separate layers of translators instead of going straight between Italian and Japanese.
Re: Ardyn, it's worth pointing out that the question was, essentially, "Will there be more about Ardyn?" rather than "Will there be an episode about Ardyn?" I think it's fair to assume he'll play a role in both Episode Prompto and Episode Ignis, so I wouldn't read too too much into the answer. ^^;
I think he'll be in both of their DLC's yes, but the focus will be solely on Prompto and Ignis.
I don't think there will be room to go into Arydn's history in those DLC's tbh. They're short, so they don't have the time or space to waste on something that isn't relevant for that particular episode.
So far, from what I can gauge, the only way to do this is a separate episode or something that's going to be added into the main game.
Since it's been established that the main game is solely from Noctis's POV, it doesn't seem likely here as well, even though that would be pretty great.
Thus my conclusion of it being a separate Episode. It's fine to disagree with me of course, no problem with that at all. But it seems like the only logical conclusion if you deduct it from what we have now, and what they're currently planning.