According to miui forums:
MIUI 9 China ROM Supported Devices:
Mi 6, Mi 5s Plus, Mi 5s, Mi 5c, Mi 5, Mi 4S, Mi 4c, Mi 4, Mi 3, Mi 2/2S, Mi MIX, Mi Max 2, Mi Max, Mi Note 2, Mi Note/Pro, Mi Pad 2, Mi Pad 1, Redmi Note 4X (MTK), Redmi Note 4X (SD), Redmi Note 4, Redmi Note 3 (MTK), Redmi Note 3 (SD), Redmi Note 2, Redmi Note, Redmi Pro, Redmi 4X, Redmi 4A, Redmi 4, Redmi 4 Prime, Redmi 3S/Prime, Redmi 3, Redmi 2A, Redmi 2/Prime, Redmi 1S, Redmi 1
So yes, it will continue to get support for now for the official ROMs. So that's something...