There will be 3 graphics modes on Xbox Series X:
Performance: Fixed 4K, no raytracing, 60 fps
Performance RT: Dynamic 4K, with raytracing (reflections and ambient occlusion), 60 fps
Visuals: Fixed 4K, with raytracing (reflections and ambient occlusion), 30 fps
Raytracing doesn’t make a big difference, ambient occlusion and reflections are hardly noticeable during regular gameplay, but still a nice touch. Dynamic resolution is also rarely noticeable, so “Performance RT” mode is highly recommended in my opinion.
So the game having both 4K, raytracing and 60 fps during gameplay is both technically true and not true. In theory it can achieve it in lighter situations but I’m sure it’s more common that dynamic resolution kicks in, in order to keep 60 fps. I hope that the framerate is rock solid in all cases.