Yes; not a lawyer, but as far as I can tell yes (and physical media too); you can, in advance (which I do), in any format you want without restriction - it’s just FLAC/MP3 etc. No DRM.
I do prefer buying full digital discography when available, because it’s such a good deal. For $30 or so, I get years and years of albums, while still supporting an artist with a much larger sum than I could via a streaming platform.
Admittedly, I’m still also using YT Music precisely for the reason I described above, and also because it makes it much easier to discover new music, compared to Bandcamp (something I’m hoping to potentially address in my own alternative).
This is a bummer! But it highlights more of an unfortunate reality we all have to deal with when buying digital goods online - always need to get a backup right away when possible, since no platform lasts forever.
