Going to pop this over into the music chat section.
Any content that is missing is normally down to the record label or rights holders with holding those tracks from Spotify (or they simply have yet to add them!), sometimes to push up physical and download sales. Have a read at this topic and this help page for a little more detail.
It's bad enough that Pendulum's album Hold Your Colour isn't on Spotify (Why, by the way?!), and what you have done now doesn't make it better in any way... Why is Pendulum's album Immersion not available in Sweden anymore?!? :'(
I see...But why is the album just available in some countries/regions? The record label for Immersion is "Warner Music UK Limited". That's the same record label that released their album In Silico...how come In Silico is still available while Immersion is not? It makes no sense...
Labels rarely do unfortunately! If you want more details, they are the people to get in touch with directly! I actually don't remember the full Immersion album ever being available here in the UK hence why I have them as local files.