I thought it might be interesting to see a poll of how people think this will go before we actually find out a few months from now. I'll take a guess and use AC Valhalla as an example. And I'll include the other consoles just for fun.
Xbox Series X = Native 4K 60FPS
PS5 = Dynamic 4K 60FPS with only minor drops from native resolution at times. Ever so slightly faster load times.
Xbox Series S = 1440P at 60FPS
Xbox One X = Dynamic resolution that hovers around 1800P at 30FPS
PS4 Pro = Dynamic resolution that hovers around 1440P at 30FPS
PS4 = 1080P at 30FPS
Xbox One S = 900P at 30FPS
So my answer would be minor advantage to Series X. Although I could see maybe some advantages in load times and with haptics/sound that even the scales a little.
Xbox Series X = Native 4K 60FPS
PS5 = Dynamic 4K 60FPS with only minor drops from native resolution at times. Ever so slightly faster load times.
Xbox Series S = 1440P at 60FPS
Xbox One X = Dynamic resolution that hovers around 1800P at 30FPS
PS4 Pro = Dynamic resolution that hovers around 1440P at 30FPS
PS4 = 1080P at 30FPS
Xbox One S = 900P at 30FPS
So my answer would be minor advantage to Series X. Although I could see maybe some advantages in load times and with haptics/sound that even the scales a little.