I really don't see Sony buying a big publisher to be honest, and also why would they?
When you look at the potential candidates they either feel like a waste of money or being out or reach for Sony. And with all these regulators shenaningans happening to MS, I dont think it would be that easy to purchase a large amount of IP.
To detail a bit more my thinking process: why would Sony buy Square Enix, Capcom, Sega or Kadokawa? These are japanese companies and have almot no chance of being bought by a non-japanese company according to japanese laws. It's not like there is a big risk of losing these companies to Microsoft or even the likes of Tencent. And as Capcom said recently, it is not like they would like to anyway.
Moreover, most of the games from these japanese publishers sell like 90% of copies on Playstation and PC, and a lot of releases skip Xbox entirely without any need for an exclusivity deal. These companies are still in need of Playstation in a way, so once again the risk of losing big IPs is minor imo.
Oh and for some of these companies, Sony hold some of their stock (they have 14% of Kadokawa for instance) which makes it even more unrealistic that they get acquired behind Sony's back (you have to tell shareholders and give them an opportunity to outbid)
Now going to the non-japanese big guns of the industry like Take 2, EA or Ubi. I would say that these companies are either way too expensive (not that Sony cannot afford it but that would be HUGE acquisitions for them), or not that relevant to Sony. Ubisoft could tick some boxes: they have long experience in GaaS, have great IPs that sold big amount of copies and also produce VR games (not that its the main reason). But with the bad press they got during recent years and the quality of their last blockbusters I would say that it wouldn't be an ideal acquisition for Sony.
I am definitely not an expert and I also know that Sony needs to move at some point, but I really can't see a huge scale acquisition of a "historical" publisher.
I would imagine Sony being more inclined to make purchase in the areas they are lacking. And looking at their last acquisitions, it seems like this is their strategy: best remake/ remastered studio in the industry (Bluepoint), a VR and PC competent studio (Firesprite), a GaaS expert (Bungie), some other PC nerds (Firewalk) etc..
The Honkai Watch devs, as already mentioned here, would be a dream move for them (no idea if this is possible tho). These guys basically print money with their GaaS and are very dominant in Asian markets that Sony is trying to tackle more.
No one would think about them, but Crytek could also be a smart move for Sony, in order to get some FPS and GaaS expertise (and IPs!). We all know they are cooking some new Crysis projets, including a GaaS, and that IP is still quite big and could make a good come back in the near future.
They also have a great GaaS with Hunt Showdown, a masterpiece of a game that also happens to print quite some money (not in the scale of a Fortnite obviously, but it is still one of the top PC online game). Also note that they have a very competent in-house Engine with CryEngine.
But hey once again I am not an expert at all, it is just all "educated" guesses.
Oh, and fuck consolidation in any case.