Android 8.0 Oreo based unofficial LineageOS 15 is now available for a wide variety of devices. Moto G4 Plus (Moto G 2016) has also received an unofficial LineageOS 15 Oreo build that you can try out on a bootloader unlocked Moto G4 Plus. Official LineageOS 15 is not yet released, however this unofficial build lets experience Android 8.0 Oreo features on Moto G4 Plus (code named athene).
Developed by an XDA member rahulsnair, the LineageOS 15 (unofficial) is not yet ready for daily use, though most aspects of the ROM are working (RIL, WiFi, Bluetooth, etc) as expected. However, experienced users who are looking for LineageOS 15 Oreo build on their Moto G4 Plus (Moto G 2016) can try out the ROM right now. Check out the below guide.
As you all know, installing LineageOS 15 Android 8.0 Oreo ROM requires unlocked bootloader and latest version of TWRP custom recovery installed on the device. If you have not already done it, read this guide.
Keep in mind that the present status of LineageOS 15 Android 8.0 Oreo ROM for Moto G4 Plus is Alpha, which means the ROM is unstable, includes several bugs and not ready for daily use.
Disclaimer: Follow the instruction at your own risk. We will not be liable if any damage occurs to your device and/or its components. This is recommended for technically talented users only.
2. Boot your Moto G4 Plus into TWRP recovery (. To do so, turn off your phone and then press and hold the Volume Down & Power buttons simultaneously for a few seconds).
3. In TWRP, select Backup and create a Nandroid backup (recommended).
4. Now, select Wipe > Advanced wipe > and wipe data, cache and dalvik cache.
Set up your new OS and experience Android 8.0 Oreo. Leave your views in the comment section below. (Source – rahulsnair)