Absolutely but they'll still approach it from a Western design perspective and because the writers are Western, the dialogue will be more suited to a Western audience. It would be like watching an incredibly well dubbed Western Movie and the problem with that is the style, presentation and moods are culturally embedded in the creation process. I CAN understand poeple wanting to play Japanese made games in Japanese though. 

Sure but that doesn't change the fact that some people will want Japanese audio for an "authentic" experience.

You're acting like your average Japanes person has enough cultural knowledge to make a culturally authentic game in this time period. They don't. The language was also most likely different back then. When it comes to authenticity in historical games the biggest issues are budget(you need to research quite a bit) and audience. Unfortunately the two usually conflict with one another. I think this game will probably have very simplistic or western-esq writing motifs, but then again cliches and themes are universal. Of course the game will focus more on making the coolest experience possible for the vast amount of people, but that's no different from any other game designer. While the audience could conflict with a feeling of authenticity, Sony is extremely respectful to their projects, from low-performers like Last Guardian to system sellers like Uncharted.

I think the game will be authentic enough to be immersive, anything else will be lost on 99% of players. If someone wants to have Japanese audio to have "that" "authentic" then I could understand why. I don't think that reasoning is particularly hard to understand. 

Still, i'll play it in english. Because that's the voice acting that the developers will pay attention too, and where the money for good VA is probably going.

We can talk all we want about research.

But the authenticit is still a thing on this.

This game made by japanese would be different than made by american even with the same theme and research, that is because their natural culture and upbring would add different elements and nuances to the game.

I won't say the impact would be tremend and that most gamers would bother. But sure I would like the budget and prowess of Sucker Punch but with the cultural approach of Japanese mindset.

Like, I can explain all I want about the tea cerimony and a movie can show it. But the real importance and meaning of it and deep roots would be inside the japanese. I'm not talking about cultural appropriation, just that there will be differences in interpretation of the theme due to the culture of the ones making it. Will play it even though.

Are you Japanese? If not, why would you want to play it in Japanese?

Game is about a Japanese conflict in Japan about Japanese people. Why would I want to play it in any other language?

Because the mongol actor is Patrick Gallagher, a famous actor? and its going to be awesome in english?

Errr I have the game and see it being played, look similar to Dark Souls/Demon Souls/Bloodborne boring "you'll day until you git good". With very little story and things to keep me entretained to justify the countless hour mastering a game I don't care about.