OpenAI has developed technology to reliably detect AI-generated text, according to inside sources and documents reported by the Wall Street Journal. However, the company is reluctant to release it, likely due to concerns about its own business model.
If they aren't willing to release it, then the situation is no different from them not having one at all. All these claims openai makes about having whatever system but hiding it, is just tobtry and increase hype to grab more investor money.