Here is your announcement I guess?
MBS-12200: Drop schema objects related to Amazon cover art support . For a long while, releases with Amazon URLs would be checked for cover art on Amazon, and if found, a link to the image would be cached for display. Unfortunately Amazon’s API to do this changed, and we haven’t synced artwork from them in years. We still have many old images cached and we still display those, but they aren’t guaranteed to be in sync. Last year we decided to drop support for displaying these, while giving time for users to upload any correct images to the Cover Art Archive. To help with this, we have a report of releases with Amazon cover art but no Cover Art Archive front cover.
I don’t know what’s up with the amazon cover art stats but it doesn’t look right.