I assumed they are workers from the studio, maybe the ones who reached X years of seniority.
No, they will be supporting during active development, which is why they need a game director. Nixes will join ICE, VASG and others in the network of support studios. It's not just about ports after the fact, that would've been a ridiculous acquisition.
Ports also need director, producer or designers. In some projects they did work in the engine and tools side, so they may help there even if their main work -at least it's what they said- will be to port games.
I assume they will have two main tasks: one to have a team who ports old games to PC, or maybe even from PSVR1 to PSVR2 if isn't full BC. The other would be to work on tweaking the engines and tools of the other PS Studios (who would be focused on making games for PS5 only) to make future/potential PC ports.
To port a console game that was originally made to target only a console requires a lot of work, specially if it uses a custom engine and wasn't developed with multiplatform on mind (other OS, APIs an libraries, different resolutions, different aspect ratio displays, different controller support -like keyboard and mouse- different quality for models/textures/LOD/etc, different trophies and interrumptions etc). Part of this work is way less painful if the engines and tools are ready for it and if the game is designer originally with it on mind.
If Sony plans to release let's say 4 PC ports of old games per year and let's say every year they start a console game or two that in the future may end be ported to PC, it's a lot of porting work. PS Studios staff pretty likely will prefer to work on original games instead of in porting, so it's better to keep them focused their talent on making PS5 games and leave PC stuff to other teams, to outsource this work. But there are many AAA games -which they became bigger and more complex every generation- and outsourcing teams are often busy working in other projects. So it's smart to buy one or two porting teams to ensure they are always ready for them. Same goes with art outsourcing support studios, Sony already had their teams but like any other AAA company outsourced a lot of work to external studios. So it's good for them to buy one or two of them (Valkyrie) to make sure are always ready for them and not busy working for someone else.
Hermen said PS Studios had over 25 games under development, so make sure that there is more than enough work to keep always busy Nixxes or Valkyrie, even one or two teams more.
Making sure the main PS Studios don't have to worry about ports make their employees happier and allows to develop their console games faster because don't have to spend time on PC stuff, so increases their console games output. And since PC ports are handled by dedicated teams who are only working on this and are very experienced on doing this, it also increases the PC ports output. A bigger output of console games and PC ports means more players happy and more revenue and profit, which later can be reinvested on hiring or acquiring people to make even more games.
I'm not sure how this has come about.
