As mentioned here, it is unfortunatly that time to deprecate the OnePlus 7/7 Pro as they have now received LineageOS 19.1 support with the requirement for the OxygenOS 12 bootloader.
What does that mean?
- Builds will continue to be created for the device, but they will remain on LineageOS 18.1.
- Builds will continue to include security updates that are published in the monthly AOSP security bulletins.
- No future major updates (like to Android 13) will be available and builds will cease based upon the device retiremeny policy.
- Installation guides and videos will not be updated.