It seems that Santa Monica Studios has clarified its involvement with development of ‘The Last Guardian’ by completely distancing itself from the game. According to Tim Moss, director of technology:
I’m never really sure how that got in the press, because as far as I’m aware we’re not helping out with The Last Guardian.
The only way you can say that is the knowledge that we contribute back to the central tech groups benefits The Last Guardian. So I’m guessing someone was slightly misquoted.
The rumor came as a result of a Wired interview last year, in which Sony Worldwide Studios boss Shuhei Yoshida made some comments that led people to believe the studio was involved in the game. Moss’s colleague Christer Ericson also added that:
The different Sony first-party teams do not necessarily actively work together, but we do communicate with each other.
We tend to visit each other several times a year, and doing so we may exchange ideas. They’ve been here, and we’ve been there. We do ask each other how are you doing that, and just sometimes go over to provide feedback.