Recently, Xiaomi announced officially MIUI 11 beta 20.3.23 and said that it would be the last update based on MIUI 11. Then reports surfaced online that the MIUI 12 beta update would start hitting devices from September, and a stable update would release by December 2020.
In the meantime, a post was shared on Weibo stating that Xiaomi Mi 10 Pro spotted on MIUI 12 based on Android 11, which is the list of devices to receive MIUI 12 updates.
Now, news has surfaced online that the company is working on MIUI 12 build, and a beta version has unknowingly leaked. Usually, Xiaomi uploads regularly, the beta versions of its several apps to the forums of Chinese MIUI Community. A couple of days ago, the Chinese OEM shared MiSettings APK on the forum.
When a junior XDA member, kacskrz, checked it, he discovered that this app has some new settings, which are very much different from the older ones.
With those leaks, it is evident that MIUI 12 will be focussing on improving its UI. It also seems that it is working on system-wide dark mode since most of the gray elements are removed. However, it is only the preliminary beta version of MIUI 12. So, it is very early to say what the end product would be.