When using the PWT or DMP The info of every disc is recorded, that includes the disc id#, name of album, artist, track list, time of each track, #times album is played/part played. I’m not sure what happens when using other digital sources, but if the albums show up in your playlist then I assume the data is being recorded.
These statistics are stored in individuals playlist.
In the background each entry of an individuals playlist is compared to the “hive” playlist and if that entry is not found you get a notice in your playlist saying “would you like to add the entry to the database (what I call the “hive”).
The hive is being used (or the intent is in future ) to identify discs being played which are not found in discogs, musicbrainz or other databases PS Audio use to identify a disc that doesn’t include all the meta-data when 1st read.
So all that data is being recorded - it makes sense that someone can make use of it to provide statistics on what we like, how much we play etc.