Im also not able to listen to certain 2pac songs/albums even though i have premium and was able to listen to these albums about a month ago. Weird hope it gets fixed soon. Guess ill be listening to Notorious B.I.G lol.
I've looked through it and it seems to be a Death Row thing at the moment. The current owner of their catalog eOne has just started to make use of their possession by releasing The Chronic by Dr. Dre on spotify and other digital platforms. I notice their youtube channel is also re-uploading a lot of stuff. In addition to 2Pac's albums in the label, they have also removed other Death Row albums from the likes of Snoop Dogg (although there's a duplicate that has not been removed yet but probably will soon).
What it tells me is that ownership has changed hands so they will reupload everything (hopefully asap) under eOne's ownership because that's how a lot of music is put up when the masters change owners. It has nothing to do with spotify itself and just a label thing that should be solved very soon.
Not sure about the rest but hit em up and California love ARE on Spotify but they’re sh*tty versions, listen to those two songs on YouTube then listen to them on Spotify and the beats are completely different. Unfortunately it’s the case for many Spotify songs and won’t be changed soon.