Yes, the model weights were developed by OpenAI. They are licensed exclusively and irrevocably to Microsoft, and operated by Microsoft, not OpenAI. If you are building with these APIs and concerned that consuming them from OpenAI (which also runs them on Azure, but managed by OpenAI staff) because of the drama there, you can de-risk by consuming from Azure directly.
>>nicce+C
Let me guess: Ilya and his team had developed GPT5, decided it very-nearly had consciousness, and then Sam immediately turned around and asked Microsoft what they're willing to pay for a copy to use and abuse.