If I recall correctly, with Cyanogenmod from the update screen I could click on a future download and see the change log. Is there anyway to restore that behavior with Lineage OS?
I have never seen that changelog list on cyanogenmod update screen but it sounds like a nice feature.
There is at least one webpage with changelog and there was a changelog app (no longer working with lineageos).However a new app is there for lineage changelog. Maybe that does help.
There is now a change-log for LineageOS, and it's prime on their download screen you can see it at https://download.lineageos.org/