I can understand that eventually only one android version will be supported but Android R is still beta and Android P builds have already been removed.
I have tested the current beta version of Android R version 19 and a major hardware feature is missing, namely WFD (WiFi Display / Wireless Display / Miracast). I think lack of Miracast support should be a major blocker before releasing stable version of Android R.
As It should be fixed I also think until it’s fixed Android Pie builds should be updated with security patches. I mean this device is still being supported by LineageOS for MicroG with both Android 9 and Android 11 builds so it’s not really much difficult to maintain the Pie builds for some time at least. There are devices that have been dropped by LineageOS but still supported by /e/ then why drop a device that is still supported by LineageOS (MicroG version).