This is true for iTunes and Google Play too, I've had albums disappear from my Library with no explanation (I suspect some licensing change or label shuffle behind the scenes). I've totally abandoned streaming services since I've been bitten twice by this.
Bandcamp handles this exceptionally well, you can download anything you buy (even as Flac!) and for anything else, it's back to buying/checking-out CDs and ripping them old-school style.
Bandcamp handles this exceptionally well, you can download anything you buy (even as Flac!) and for anything else, it's back to buying/checking-out CDs and ripping them old-school style.