Right now, Assassin's Creed Shadows already lets you pick between easy, normal, and expert difficulty options for combat and stealth. Bumping up the stealth sections makes enemies more alert, meaning you can't just run around on rooftops expecting enemies to not look up, so I dread to think about how much tougher Ubisoft can make it.
You may remember that Ghost of Tsushima ended up being a blockbuster in Japan for Sony and Sucker Punch — but it doesn't look like Shadows is going to enjoy anything close to that level of success. A shame, perhaps, given that Japanese reviews have been positive.