I've read some news that Xiaomi posted on chinese Mi Community on beginning of september a list of devices that are dropped from function updates. It was 8 series, Max 3 and Mix 2S and 3. This means we shouldn't count on it to get Android 11. MIUI 13? Maybe, Mi Mix 2 has been updated to MIUI 12, but it stays on Android 9 and will not receive 10.