Some things cannot be directly translated, and in some other cases the translation will be tailored to their intended audience. A Japanese (native) speaker playing the game with English voices would be very surprised by the use of the language, mostly because it's something they may not be used to hearing (i.e Shakespearean type words), and there may not be a direct equivalent in their own tongue. It does specifically state in the settings that having audio different to your client may not always match so it's to be expected that is not entirely the same in all languages (because it's just not always possible to do that).