In a recent Dengeki Online (via VGC) interview, producer Naoki Yoshida said that because Final Fantasy 16 is set in the classic European medieval environment, the English-language Final Fantasy 16 audio will feature British English accents only. Speaking on a recent Japanese Internet show called Washanaga (translated by Siliconera), producer Naoki Yoshida said the development team at Square Enix has chosen English-accented voice actors to portray game characters, and Japanese game production is starting soon.

Speaking with Japanese publication Dengeki Online, the producers of Final Fantasy 16 said all voice work and motion capture for Final Fantasy 16 was done with European actors in order not to violate expectations from American players, who expect setting characters to be British-accented.
Final Fantasy 16 producers confirmed Final Fantasy 16 will use only British English, with no American accents, in order to convey the game’s medieval European setting. Final Fantasy 16s producers announced the game would not feature American accents on characters out of concerns they would not be accepted by American players because of its medieval Europe-inspired setting.
Final Fantasy 16 Producer Naoki Yoshidas producer further explained that he and his development team initially wrote the game’s story in Japanese, then translated it to English for English speakers. In an interview with Dengeki Online, Naoki Yoshida explained that he and his development team focused on making European settings come alive, combining that with fantasy elements the franchise is known for.
Yoshi-P is very aware of specifically Americans +their complaints on English voice acting lol.
For FF16, they made sure NOT to include any American accents to prevent Americans from getting upset thinking "if it's in fantasy Medieval Europe, why do they speak American English!?" pic.twitter.com/UrFdtN0tzA
— ☆オードリーAudrey☆ (@aitaikimochi) June 23, 2022
Yoshida was asked about the movement and facial capture work of FF 16, as well as why publisher Square Enix decided to only use European accents rather than Americans. During a recent interview, the game’s producer revealed that the upcoming installment of Square Enix’s long-running series will be using English as the main language and dialect.
Square Enix’s upcoming FF 16 action RPG will prioritize English voice acting, according to the game’s producer. Yoshida said the Japanese version would soon have the same treatment, though it was unclear whether the games will have completely separate facial capture for English and Japanese versions. Square Enix was concerned that characters speaking English in the US language would frustrate American players hoping for a realistic depiction of medieval Europe.
We heard earlier that voiceover work is almost finished, and the game is probably skipping Tokyo Game Show, since Yoshida wants to reveal it as soon as it is finished, instead of showing snippets of a finished product. We have all of the scenarios already in place, and English recording for the English release of the game is at the very end stages. According to Final Fantasy XVI producers, they are prioritizing English recordings over Japanese audio recordings, a move that is rather surprising.