This is different. The game has dual TEXT. Not just optional character voices. But the essential menus and dialog will be in Japanese as well.
We don't know. Most supposed paid DLC is never actually proven to be that. Or even then, if the console maker is who paid out.
These deals when they occur, are done behind closed doors heavily defended under NDA agreements.
People always happen to "forget" that MS did not publish the PC version. A proverbial elephant in the room even MS's own statement didn't address.