Ubsofts offers the next gen upgrade for free from December 1st 2020. “The best Siege experience on next-gen consoles is here. Upgrade free to the Xbox Series X or PlayStation 5 version of Rainbow Six Siege to play with 4K visuals and up to 120 FPS.”
Ubisoft showcase the Xbox Series X version of Watch Dogs Legion in this video which highlights the game running at 4K 30 fps with ray tracing enabled. That’s some serious optimization.