The Lineage OS team is now working on LineageOS 15 based on the latest Android 8.0 Oreo. OnePlus One will be the first device to get LineageOS 15, which means OnePlus One users can enjoy Android 8.0 Oreo and its features soon. As you all know, OnePlus One will not get support from OnePlus as it is a too old device, so no official Android Oreo update.
The Lineage OS team already started to build Android 8.0 Oreo based LineageOS 15 and its Lineage Project information page reveals that OnePlus One (Bacon) will be the first device to get the all new LineageOS 15. The team posted development files of LinageOS 15 for the OnePlus One on their website. However the release date is unclear now.
If everything goes fine, OnePlus One will get the Android 8.0 Oreo update soon via LineageOS 15. We will provide download and other installation information once it is ready.
Android 8.0 Oreo is the major Android OS update and it offers performance enhancements and bunch of new features to your phone. However, not all phones are eligible for Android 8.0 Oreo update, but custom ROM like LineageOS 15 can bring the Oreo update.
We will provide details and other LineageOS 15 news in the coming posts, so stay tuned. (source)