I guess they are excluding Funk, which explains no Parliament or Funkadelic.
I saw Parliament / Funkadelic at the Cotton Bowl in 1979 or so. It was called the Funk Festival. Bootsy Collins, Rick James, BarKays, ConFunkShun, and a few others. There weren’t too many of us crackers there.
It’s a very myopic list, 3 albums by several repeated artists and even 3 soundtracks.