The update was released for EEA and Global regions with build numbers V22.214.171.124.RJEEUXM and V126.96.36.199.RJEMIXM, respectively. The firmware has a Stable Beta prefix, which means that a limited number of users have begun to receive it so far. If there are no bugs in the software, then in the near future the system will be released for everyone.
As for the list of changes, it is standard here. The smartphone received major changes to Android 11, as well as all the major innovations of MIUI 12.5. As a reminder, this is a new interface, improved animation, new live wallpapers, advanced privacy settings and much more.