I'm sure they pointed that way for TV content, too, when Netflix did House of Cards.
I think people want music that's "well known", music their peers also know about, and that goal is aligned with the big four labels, because they have the clout/infrastructure to get a song played on the radio etc., but it's not a causal relationship. With streaming becoming ever more popular, the idea that Spotify could achieve something similar, especially if they can tap into data to predict who's likely to like a new album, isn't too farfetched.
Some of the most talked-about shows in the country were only on cable.
Its hard to say if the discovery products are supposed to guide users to less expensive content, but is is an interesting theory. But showing users content they might not be aware of would necessarily go beyond the big labels that are everywhere. I think it has more to do with providing value that can't escape the platform due to external factors such as a label striking a deal with a competitor.
This doesn't work for Sony BMG of course, but consider a label like Ghostly International. Come for Tycho, find Com Truise, Lord Raja, Gold Panda, Shigeto, others).