Still competition for cerebras. Seems quite unlikely they will get an OpenAI deal anytime soon.

They have an OpenAI deal right now. https://openai.com/index/cerebras-partnership/

No - this is OpenAI trying to complete with Google (TPU) and Amazon/Anthropic (Trainium) on cost.

Cerebras are addressing very specific use cases, not general purpose LLM serving, and OpenAI does already partner with them.