To no surprise. Pretty much all their second party partners have now been acquired by them, that leaves the more interesting third party acquisitions.
I reckon Sony is going all in. The Pictures CEO hinted at SIE's spend and iirc Sony expect to spend $18B on investments in the next three years. PS is Sony's biggest division, you bet a lot is going into gaming.
Now it may not all be acquisitions or devs. For instance Sony invested in Epic, Kadokawa and Discord. They bought Evo and a while ago wWise and Gakai (PS Now).
IMO these are the studios/pubs most likely:
- From Software
- Kojima Productions
- Arrowhead
- Camoflauj
- Ember Lab
- Square Enix