Yasuke is actually a fantastic choice as far as history/narrative goes.
A shame the game looks like more generic Assassin’s Creed Mapfucking+Crowd Supermurder.
Which is fine if that’s your thing, but I haven’t been thrilled by an AC game since… well, AC1.
They showed some gameplay that had one character collect information, and then you get a checkpoint of sorts before the actual mission where you choose which character to use. Yasuke can bust up the front door and whack everyone, or Naoe can climb the walls and crawl underwater. It’s suggested that this is most of the game, but it’s safe to presume there will be some missions here and there that require a specific character.