The Mi CC9e and Redmi Note 8 Pro have received new MIUI 12 upgrades spanning several branches of MIUI, but the Redmi 8 and Redmi Note 8 are in no such luck. Instead, the Redmi 8 and Redmi Note 8 have just received security updates in multiple regions, keeping the devices on MIUI 11 for the time being.
https://www.notebookcheck.net/Xiaomi-Mi-CC9e-and-Redmi-Note-8-Pro-receive-new-MIUI-12-upgrades-as-the-Redmi-8-and-Redmi-Note-8-pick-up-perfunctory-updates.498920.0.html