The main translator who worked on XIII, Tom Slattery, I think, is no longer at Square Enix, and he shared details about his role as localizer. The project seemed to be a nightmare to bring to life. (On that note, Alexander O. Smith does not seem to be in charge of XV's localization.)
The question is why the localizers have deemed it appropriate to change the way that Ignis addresses Noctis. I made a simplistic comment in the first place, so thank you for explaining.