http://www.techradar.com/news/android-oreo-update-lands-on-oneplus-3-and-oneplus-3t

If you’re struggling to resist moving from a OnePlus 3 or OnePlus 3T to a OnePlus 5T, today’s news might make it a better easier, as the OnePlus 3 and 3T are now being upgraded to Android Oreo.

The over the air update actually gives you OxygenOS 5.0, which is Android Oreo plus some of the company’s own additions.