The Mi 8 Pro is set to receive its inaugural MIUI 12 update this week, according to Xiaomi. The company has pulled back MIUI 12 for the Poco X2 because of bugs though and has suggested that the Pocophone F1 may not receive its latest OS until September at the earliest.
https://www.notebookcheck.net/Stable-MIUI-12-arriving-this-week-for-the-Mi-8-Pro-as-Xiaomi-pulls-bug-ridden-update-for-the-Poco-X2-and-hints-at-a-September-release-for-the-Pocophone-F1.484864.0.html