OnePlus already started beta testing Android 8.0 Oreo for the OnePlus 3 earlier this month, mentioning that a rollout would eventually hit the 3T and OnePlus 5. Unfortunately, they weren’t ready to commit to any sort of release window, only making their intentions known but little else.
It seems testing for Oreo on the OnePlus 5 may have already begun, with the OnePlus 5 spotted on Geekbench running Android 8.0. Whether this benchmark was performed internally or in a closed test — it seems a public beta may not be far behind.
While there’s no official release date for Android 8.0 Oreo on the OnePlus 3/3T and OnePlus 5, it’s entirely possible we could see the update arrive before year’s end. That’s one of the benefits you get when you sell an unlocked device and don’t need carrier approval.