Apple has changed the way the MiniStore works; now you see this explanatory screen. The screen replaces the MiniStore area of the iTunes window, and explains what the MiniStore does, and how to turn it off. It states that “Apple does not keep any information related to the contents of your music Library” and asks if you would like to turn on the MiniStore now, with a button.
Much better Apple; thanks.
SetApp: A Suite of macOS Apps for a Single Price Affiliate link for a great collection of 200+ macOS apps for a single price—now with iOS apps too.