Xiaomi announced the Mi A2 under the Android One program back in July 2018. The smartphone was launched running Android 8.1 (Oreo), and the company updated it to Android 9.0 (Pie) in December 2018. Android One devices from other brands such as HMD and Motorola have already received Android 10 update, as per the Android One policy, the Mi A2 is eligible to receive Android 10 update.
As per posts on Mi Community, Xiaomi has started rolling out Android 10 update to Mi A2 users in various regions including India, Brasil, Finland, Colombia, Portugal. The update comes with version 188.8.131.52.QDIMIXM, weighs about 1283 MBs in size and has December Android security patch. Android 10 brings a number of additional privacy and security features for users, as well as Dark Theme, Smart Reply, Focus mode, dedicated ‘Privacy section’, and lots more.
Xiaomi Mi A3 and Mi A2 Lite are yet to receive Android 10 update, the Mi A3 might receive Android 10 update soon since the company has already released Android 10 based kernel sources for the device.