Mate, if they're "involved" in the game it's going to be that they were responsible for the port ("PC team"). I mean, if they didn't do the port how exactly do you think that they were involved? Responsible for making the tea and biscuits? They've made around seven basic, minor games for themselves in 10 years, but have done over 50 ports. They're even front and centre on the requirement specs sheet from Naughty Dog themselves, just prior to launch:
Also there's this:""Our team, and our dedicated partners at Iron Galaxy will continue to investigate and address known issues to deliver the great The Last of Us Part I experience you expect," the developer says.
End of the day I'm just fucked-off at yet another shitty PC port. I'm not sure why the in-house comment from Naughty Dog. Perhaps it sounded better than "hey, we've given it to the Arkham Knight guys".
As for the steam page, Nixxes were originally listed as the developer:
https://preview.redd.it/0w7kgjioe9m91.png?width=7582&format=png&auto=webp&v=enabled&s=f44731e85e22a85471b063c72318091c5ffd1eebThere's more going on than meets the eye.