Can certain albums/songs be "hidden", but still playable?

[LyteSpawn]

So, bear with me for a sec here. I was just looking through Rise Against's page, and here you can see that their earliest album is Siren Song of the Counter-Culture, from 2004. However, this isn't their first album. They have two previous ones, The Unraveling (2001) and Revolutions Per Minute (2003), which their Spotify page appears to be missing, or so it seems.

Now, if you google the band name and one of those albums, you can actually find them on Spotify, as seen here and here. And they're even playable.

Now my question is, why are they hidden from their Spotify page, and is there any way to get them to show?

Thanks!