Xiaomi's flagship phones are already on their way to Android 11 but things aren't quite as cosy on the lower-end of the heirarchy. The Mi Mix 2S, for example, has been said not to receive the update. The Redmi 8A is another phone with slim prospects, too.
https://www.notebookcheck.net/No-Android-11-for-the-Mi-Mix-2S-Redmi-8A-prospects-slim-too-but-MIUI-12-release-imminent.480892.0.html