It seems that the Lineage OS team will not release LineageOS 15 we are all expected. The team is now setting up to release LineageOS 15.1 based on Android 8.1 Oreo, as Google has released stable builds of Android 8.1. In a recent post about changes to the latest official builds, the Lineage OS team informed that they are moving straight to the LineageOS 15.1 builds by skipping the 15 builds.
Since the release of Android 8.0 Oreo, the company has been working on LineageOS 15.0, but instead of releasing those builds, now they are merging all their work with the release of LineageOS 15.1. However, as usual the release date of LineageOS 15.1 not yet revealed. You can expect first builds anytime soon.
At the same time, several unofficial LineageOS 15 builds are already available for several devices (check our unofficial LinegaeOS 15 guides).These builds are obviously based on the official LOS 15.0 source code available on Github.
The LineageOS team has updated LineageOS 14.1 with several changes, improvements and support for more devices. The update fixes the KRACK Wi-Fi vulnerability, includes November 2017 security patches, supports extended length NFC, and more. Check full details here.
Besides the long list of supported devices, the updated LineageOS 14.1 builds are now available for more devices, such as LG K10, Sony Xperia Z4 Tablet, Sony Xperia Z5 Compact, Fairphone 2, BQ Aquaris X5 Plus, etc.
One of the main advantages of Lineage OS custom ROM (former CyanogenMod) is that it updates many devices to the newer version of Android OS before the manufacturer has officially made available.
Also, many older devices will get the latest Android version (here Android 8.1 Oreo) via LineageOS 15.1, even if the manufacturer stopped support for software upgrade.
LineageOS fans can expect first build of LineageOS 15.1 anytime soon. We’ll keep you updated with every news of the LineageOS 151. (Source)