The alleged main updates for MIUI 13 have been leaked just as a supposed image of the redesigned Control Center has started doing the rounds. One of the purported MIUI 13 changes is the introduction of floating windows for games. It is widely believed Xiaomi will officially reveal its latest Android overlay in mid-August.
https://www.notebookcheck.net/MIUI-13-main-updates-leaked-along-with-the-supposed-Control-Center-design-for-Xiaomi-s-upcoming-Android-overlay.551695.0.html