Vivo has started to rollout the Android 10 update based on Funtouch OS 10 for Vivo V15 under Greyscale testing.
Some users should have already received the update. Since, there’s no confirmation that the all users have received the update or not.
The update rolling out in Greyscale is similar to the limited rollout. This means that after the update is ready, the company chooses to roll it out to select users, to ensure that there are no major bugs before the update rolls out to more devices.
The Greyscale testing is underway for the Vivo V15 and soon the stable Android 10 update will arrive. After the testing is successful then, the stable update began rolling out to all the users.