I think a harbinger of this was the fact that the latest console generation did not come with an upgrade in (physical) game medium. Previously, each console generation came with newer cartridges, then with newer disc formats (CD, then DVD, then HD-DVD / Blu Ray). But this generation just stuck with Blu Ray. That signaled to me that this may very well be the last generation to even support physical media. If this cons…
The reason Sony upgrades media on its consoles is that Sony is a holding that also holds companies developing the said media and companies distributing movies/music on the same media. It's a cross-promotion.