Assassin's Creed: Shadows will feature two playable heroes: the ninja Naoe and the samurai Yasuké. According to the developers, the gameplay for each will be different, but if desired, almost the entire game can be completed with just one character.
Most of the content can be played by either character, and there's no hard gating that says this is a Naoe thing. Story moments are character focused, but the rest of the game is open.
However, the game will still encourage switching characters — this will happen through playstyle and loot.
Progression incentivises you to switch, because when you play just one character for a while, they will pick up stuff for the other character to use. So both characters kind of progress together.
Assassin's Creed: Shadows will be released on November 15 for PC, Xbox Series X/S, and PS5. Deluxe edition owners will be able to start the game on the 12th.