The new feature was recently launched with a number of games which were released earlier. Now these are games like The Elder Scrolls V: Skyrim, Fallout 4, Prey, Dishonored: Definitive Edition and some others from Bethesda.
This was announced by Aaron Greenberg, the head of Microsoft during a general conference with representatives of Bethesda. More games will be announced in the future that will support this feature. For now, this will only apply to releases from Bethesda.
It is important that for advertised games you will be able to use a higher frame rate and have better performance. This feature was announced immediately following user complaints about bugs when launching previous generation games. Now you can play your favorite games smoother with the more powerful Xbox Series X/S processor.