I love how new random definitions just come out of nowhere into existence mainly for the purpose of further compartmentalization for regulatory purposes. Seriously, when was "premium games" used to describe game sales in prior generations?
It's the same as the "high-end console market" term; loaded term that was only spun up by regulators to exclude Nintendo in market share comparisons between PlayStation and Xbox. Now I see tons of people on all sides using the term like it's legit; it was literally invented a year ago to describe a market segment that already had a term for it previously (home consoles) which came organically, not out of a regulatory reviewal processs.
But back on track to the thread topic..OP no I don't think Sony makes a move to buy Valve and I don't think they are interested in doing that anytime soon if ever. The day Sony prioritizes a PC launcher/storefront is the day they have to start preparing to substantial drop-off of home console sales, as they'd inevitably need to prioritize Day 1 availability of their 1P games on said launcher.
Giving more reason for hardcore and core enthusiasts, who are almost always early adopters, to go PC for future hardware and not buy PlayStation consoles. Meaning that's a decent chunk of hardware sales revenue gone overnight. Sony would have to find a way to replace that through the launcher/storefront, with a mix of ad-supported/sponsored tiers and customer-pay sub tiers with various levels of content and perks tied to them, respective of the tier.
Honestly it's not a reality Sony have to consider until at least 10 years out from now; even then I think they'd be better off "microcomputer-izing" the PlayStation systems before finally shifting a key component of the ecosystem stack to an open platform they can't have any standardization of control over.
