Yeah, it weakly supports his position that advanced AIs can deliberately cooperate in a prisoner dilemma. "Weakly", because the said AIs share a lot of data (their weights, training methods, system prompts) and it's unknown whether they explicitly framed the situation as a prisoner dilemma.

Given the public information in the reports, it seems to me a bit more like a generalized tendency to play along (sort of like what we see with prompt injections) than explicit game-theoretic cooperation, but it's hard to tell given that there are so many details we aren't privy to.