FFXIV was actually the first thing to pop in my head, as it is far and away SE's biggest title, and it seems to fit into Sony's new approach on GaaS/MP games. Guess I don't qualify since I'm one of the few big FFXIV fans 'round here :P
But I'm of the opinion that FFXIV is about to reach its peak if it hadn't already. It's essentially a downgraded PS3 MMO, the visual upgrades its receiving soon will not mask its inherent flaws. Pretty crazy to me that it's still going strong.
Moneyhatting is kinda all the more reason for Sony to acquire SquareEnix. It shows how much they still care about their content. Rather than moneyhatting them for say a dozen titles over the generation, why not acquire them and make the money back through the new added revenue stream? Constant moneyhatting is shortsighted if you got the resources to buy the entire company, which is pretty much a gigantic moneyhat in anything but name, efficiency, and control. They'd retain the option to sell them later down the road if things didn't go as well as they hoped.
They can choose to keep everything exactly as it is and still benefit greatly in the long run. And... they can choose to make more games exclusive to push console sales when production exceeds demand. Having complete control and 100% the revenue streams is more effective than moneyhatting. To top it off, there is always the threat of another platform holder buying them, or the SE management pulling a Konami.
But yeah, it's certainly nowhere near the level of Zenimax acquisition as far as pushing console sales, let alone Activison Blizzard. Didn't really calculate it in mind but I'd argue that removing Bethesda's games off Playstation may affect more PS players than removing ALL Capcom/SquareEnix/FromSoftware (okay maybe not Elden Ring) games combined from Xbox would affect Xbox players. So yes, it'd be a pretty tame acquisition in that sense.
Well, you didn't mention Final Fantasy XIV in the post that preceded mine, so it really looked like nobody was thinking about it.
FF XIV should remain strong for a while longer, because I think there isn't any serious competitor in the making right now. It's even likely that the only game that will replace FF XIV as the go-to MMORPG is its sequel that runs on a more modern engine, so Final Fantasy XVII or whatever S-E chooses to call it.
I am not convinced that buying S-E outright is more profitable than targeted moneyhats in the long run. Many of S-E's big projects suffer from mismanagement that results in development times much longer than their original target, and being under the safe umbrella of SIE may lead to even more prolonged development times because there's less financial pressure to deliver on time.
As for the threat of another platform holder buying them, there's really only Microsoft who would do it, but I doubt they would want to ruin the goodwill they've been able to build in the past few years. Acquiring Square-Enix would put them right back in the place of being the soulless corporation that buys things to lock them away from other platform's fanbases. There's a reason why Microsoft has been so ambigious in response to the question whether PS will lose access to Call of Duty and the like. And the other threat - SE pulling a Konami - is simply unrealistic. Konami has always been a company about more than video games, so video games have not been their core business like it is the case for S-E. The biggest threat that I see is that S-E makes self-destructive business decisions with the pursuit of blockchains and the like, which would devalue the IPs that they have.
Like I said, I put the odds for an acquistion at 50/50. There are reasons why it can make sense for both Sony and Square-Enix, but there are also good reasons for why it is a redundant/unnecessary buyout.