I'm not sure it actually makes a difference. OpenAI doesn't care about the million dollars in any case. And the judgement that they did it is independent of whether the Clay people agree: you can make up your own mind and so can everyone else.
Though it would be funny if no one ever bothers publishing the result in an appropriate journal, and thus the prize technically can never be claimed.
Even funnier that it wouldn't even be the first time that happens: https://en.wikipedia.org/wiki/Grigori_Perelman