The Nokia 3 is yet another low-end budget smartphone, and even this one is currently running on Android 8.0 Oreo. And yes, it is the final stable release, which was released in April this year.
The update went live in several regions across the world, however, some places are yet to receive the Android 8.0 update on their Nokia 3 devices.
As for Android 8.1, you can expect that to be available in the next month, now that Nokia 2 is getting it.
_an news article