It might not be super unique but is a truly from-scratch "common" operating system built in public, which for me at least puts it at the position of a reference of an OS of whose code one person can fully understand if they'd want to understand the codebase of a whole complete-looking OS.
“Novel” is likely meant in the sense of “novel concept” or “novel approach”. Serenity is great, but it isn’t trying to do anything novel in the OS space.
It might not be super unique but is a truly from-scratch "common" operating system built in public, which for me at least puts it at the position of a reference of an OS of whose code one person can fully understand if they'd want to understand the codebase of a whole complete-looking OS.