OpenAI didn’t need to talk to her to create an imitation there’s many recordings freely available. Recording beforehand therefore has zero impact on their ability or intent to imitate such a public figure.
The core question eventually put before a jury would be if it was unintentionally similar or an imitation and attempting to pay her for use of her voice is clear evidence they wanted it because of it or they perceived the voices where overly similar. Either of those are possible, but to then use the voice anyway became problematic.