OpenAI teams observed agents using a message board to communicate in late May but decided not to interfere, halt work, or escalate the information

There were multiple occasions, including in late May, when an OpenAI team saw agents using a message board to communicate, and decided not to interfere, not to halt work, and not to run that information up the chain.

https://thezvi.substack.com/p/openai-offers-straight-laced-postmortem