Cerebras features in the internal OpenAI emails that recently came out. One example:
Ilya Sutskever to Elon Musk, Sam Altman, (cc: Greg Brockman, Sam Teller, Shivon Zilis) - Sep 20, 2017 2:08 PM
> In the event we decide to buy Cerebras, my strong sense is that it'll be done through Tesla. But why do it this way if we could also do it from within OpenAI?