Yep.
I think that if Sony or MS continue acquiring big publishers, they'll do as they did with Mojang or Bungie (and for the most part, what they did wih Zenimax): to keep all their games full multiplatform in other console and just blocking exclusives for rival companies, maybe keeping some small exclusive for themselves as rare exceptions from time to them.
That would help them maximize the amount of money they make. I also think that would be more profitable to acquire new studios with talented, proven and experienced teams they already know and have a great potential. As an example, the team who made Stray, whose staff came mostly from Quantic Dream and Ubisoft Montpellier and Ubisoft Paris.
They did a great job with Stray. With Sony helping them to grow, giving them more time and resources plus helping them in many areas they could easily become a top tier prestige studio.
It would be very cheap to acquire, market regulators wouldn't complain about it and with their first successful AAA game they'd recoup the acquisition costs. Big publishers instead are very expensive to be acquired and to recoup that inversion would take many years (and with MS's current business model, if they make all or most of their games console exclusives I'd say they never recoup the investment).
I think both you and Remember_Spinal need to see the big picture, because you have hippie-like glasses on. You're talking about things as if the business market itself operates in practice on fair grounds; it doesn't. Sony doing things like they did with Stray is great, but that alone cannot be their solution to a creeping reality of market consolidation.
They. Need. Big. Known. IPs. That's just a simple fact. They have some already, obviously, but could always stand to use more. They need more teams in-house that can fully leverage those IP. They need game type and genre variety for portfolio offering on the market where they have full ownership. They need those types of assets to leverage against other direct competitors who threaten their bottom line, and those are things 3P publisher acquisitions will inevitably end up helping with.
Sony helping with Stray is fine and all, but what's the long-term benefit for Sony if Stray's developer or IP owner ends up acquired by a direct competitor who has no shyness in foreclosing access of that game (or certainly, the studio) off PlayStation? What benefit is there long-term in providing a lucrative platform for a game like Fortnite if its own parent company's owner is trying to throw you under the bus in a court case that doesn't even really concern you? The fact is, you can't really trust how other parties may play things out over the long-term unless they're fully integrated into the circle. WRT game studios, publishers, IP and the sort, that's going to involve either majority shares or M&As (or, likely, both).
You and others are too scared of these regulators; if Microsoft can finesse them, Sony can as well. Though Sony would not need to finesse them at all to get bigger M&As approved; they'd simply have to redefine the contexts in whom they are dealing with in the competitive market, the goals of competitors, their size and resources compared to much bigger companies in the tech space who have gotten aggressive with M&As in gaming. They'd also need to emphasize that PlayStation's market share is a "fair" monopoly (if even that, which requires you ignore Nintendo) that was earned through customers in the market choosing to buy their product over competitors (it is not their fault companies like Microsoft are bad at convincing customers to buy their own gaming products).
There are very strong means to build a case where even with PlayStation's market share in the traditional console gaming space, they can paint the picture that being blocked from acquiring a larger 3P publisher betrays the principals of what an open capitalist market is meant to stand for. That they, in effect, are being punished for their success in the industry, and rather unfairly. It could also be argued that Microsoft's M&As, as an example, run the threat of destabilizing the market because Microsoft as a platform holder has displayed poor means of retaining & growing their gaming brand's revenue and software output quality over many years, with a significantly smaller number of in-house studios than they have today. Why should the company with the worst track record in providing appealing solutions in the market for developers, publishers, and customers...be the one allowed to make these big 3P acquisitions? Just because they have the money to do so? Money that is earned through sectors outside of the gaming market, mind.
It isn't the job of regulators to artificially create a balance in the market by allowing a 3rd place competitor to buy their way into the realm of the 1st place competitor. But if they would seek to block a company like Sony from making a large gaming M&A of their own simply because of their position in the industry based off revenue (keeping in mind, most of that is directly attributable to 3P publisher sales, so if a 3P has a bad year, Sony have no control over that portion of dropped revenue), then a case could be made that those regulators themselves are not fit to regulate. Especially when that position was earned through fair competition and leveraging partnerships, deals & investments that have historically been deemed perfectly fine in markets for fair competition.
You don't get to suddenly, retroactively rewrite those rules, when you ignored violations of those very same rules many years prior by almost all of these Big Tech companies.