Earlier today, I received some assistance in locating the previous library link within my overall Music library, subgroup, iTunes. In this regard, I was able to identify and recover the playlists that has disappeared from my iTunes library.
It’s almost as if there’s a little iTunes wizard who targets those of us who don’t purchase songs from iTunes, yet use the platform to create and build a music library, securing songs from other sources outside of iTunes and this wizard,
in reprisal, just removes specific tracks, as they choose. Sounds like the Twilight Zone: a show that I grew up with and still watch in re-run.