I think Insomniac like their independence. They have had talks in the past I'm sure and Sony was unable to convince them.

Quantic Dream I think won't be getting much more funding from Sony if this game fails to sell well. Although the games are decent, they are a bit like Marmite. I enjoyed Heavy Rain, but Beyond although good was never a must buy for me and from the looks of it others felt the same. Judging by the sales of Detroit, it may suffer a similar fate to Beyond. Quantic is very much a one tick pony that only makes one type of game and now Super Massive probably proved they could make similar games in a shorter time with less money. 

Ready At Dawn needs to deliver. So far they have been mediocre at best without a big IP and Sony devs to carry them. However, I would love to see what Ready At Dawn could do with a bit more time and money if they were to make a sequel to The Order (although I would prefer the IP be given to SSM or the old Guerilla Cambridge).

falcom or capcom, sony really need to go back with their JRPG titles they're lacking this gen outside 3rd party

im not sure personally. good points in above posts along with really good studios. i can disagree with one in particular as i believe it would be a very bad investment is Quantic Dream. the rest i read about could work well if the studio decided to go that way. who knows.

its hard when they already have a really good stride going with what they have with more on the way, i know, its not time to stop or get complacent, got to keep the pressure up and as well as get some more working games on ps5 launch titles.

Insomniac would be a huge get if possible.

Bluepoint if the price is right, theyve put in good work (with remasters/collections ect).
I actually think you could scale this studio up, and put them to work on their own projects too if wanted/needed.

*edit:
Id put Bluepoint to work on a Legend of Dragoon rework game (first), and ask them to stay faithfull to original.
Then I'd get a 2nd studio to work on a new Legend of the Dragoon game.

From Software, Konami and Capcom for strong ips, Bluepoint + expansion to bring back all ps1,2 and 3 games.
For multiplayer, thirds already make the job, like fortinite.

I think they need a top tier JRPG. They are Sony, a huge japanese company and they don't have something for their own audience. Nintendo has Xenoblade, Sony could revive an old ip or create a new one. They also could try their hands at hunting games again after the success of Soul Sacrifice, Freedom Wars, and Monster Hunter World.

I'd be fine if Sony took over under-performing studios that share its design philosophy: story and characters above all else. So maybe what's left of Ready at Dawn? Quantic Dream? Dontnod? Fullbright, maybe?

I do not want the publisher to purchase a studio like Insomniac or From Software. I think being more beholden to Sony would be a negative thing. Plus, the PlayStation ecosystem is going to get exclusive games from those partners anyway.

Sony's tried to acquire Insomniac before. Insomniac wanted to stay independent. That said, Insomniac continues to have a very good working relationship with Sony.
My guess is that Sony is going to attempt to pick up Kojima Productions after Death Stranding is released unless it bombs hard.

Bluepoint is exceptional at porting games. I figure Sony is probably going to give them a chance at developing their own game at some point in the future.

Sony doesn't need to buy studios, they need to create new teams inside the studios they already have. Create teams inside the same studio is a much better aproach for someone whit as many studios as sony since costs are lower, the teams can colaborate to deliver more polished games and the studios "pedigree" ( that naugthy dog logo make the game way more attractive ) can be used to generate more sales for new ip.

Exception: If a big name developer, like kojima, comes to sony and ask for a new studio, than sony needs to create a new studio for this guy! "kojima" level developers are rare and sell games by just putting their names in the credits, if they wants to work whit sony exclusives sony must create a studio for the guy or colaborate whit it to create the game.

@ bold: Why would it be a negative thing? If anything, Sony are quite hands off and give enough creative freedom to their own studios while bankrolling their projects. Case in point Guerrilla Games and their transition from an FPS type of studio to making something like Horizon. Or the fact that Polyphony seems to have free reign to create 1 full game per console generation and no heads roll.

So, yeah... what's the negative there?