OnePlus has started pushing out a new update to the OnePlus 3 closed beta group. Weighing in at around 800MB, the update in question brings Android 8.0 Oreo. The update, unsurprisingly, isn't stable - NFC isn't functional yet, WiFi is buggy, hotspot and Bluetooth is unstable, and so on. The Chinese company is aiming to roll out the stable build by mid-September. It's worth mentioning that the OnePlus 3T and 5 closed beta groups are also expected to get the Oreo update soon. Time-frame for their respective stable builds is same as that of the OnePlus 3, which is...
Source: http://www.gsmarena.com/oreo_update_starts_rolling_out_to_oneplus_3_closed_beta_channel-news-27150.php