They also have four Persona games to translate within the next year-ish as it is, which wasn't a known variable at the time of the Sega buyout when that theory was being floated. Obviously it's probably not going on simultaneously, but speaking from experience, having just one game on a translator's plate is bound to eat up a good chunk of time if you want them to take their time and make the localization shine, but four would definitely keep most any team of that size busy for quite some time, especially if Arena Ultimax in particularly turns out to be as verbose as its predecessor. Short of doing a staff expansion, throwing another super verbose game like a Yakuza is probably expecting too much, no matter how good that translation team is.
Plus, if I'm not mistaken, save for the technical implementation of localizations, I'm pretty sure the bulk of localization work for Yakuza games has typically been outsourced since, Atlus aside, I don't think Sega has had a proper internal localization team for quite a number of years now based on what I read about how the previous main games were brought over into English. Of course you're free to ask at that point why they might not be exercising even that option if we're to (understandably!) take that response to really mean they're not working on it and it's not just a case of them not being ready to announce something, to which I would say I don't have any insight into any internal data or decision making going on there that's influencing this stuff.
