No official release notes for now, but some reddit folks already managed to port the updated files to games that already support DLSS and noticed no fps performance increase. However, the new version does fix some visual artifacts and further improves image quality. Rainbow Six Siege is supposed to get an fps boost of up to 50% in 4K, but the implementation is not that good as HUD elements are displayed at rendering resolution instead of native resolution.
https://www.notebookcheck.net/Nvidia-sneaks-DLSS-2-2-update-with-latest-Rainbow-Six-Siege-patch.545963.0.html