OpenAI's mistake was caving to SJ. They should have kept Sky and told SJ to get lost. If SJ sued, they could simply prove another voice actor was used and make the legitimate argument that SJ doesn't have a monopoly on voices similar to hers.
OpenAI should’ve owned their actions. "Yes, we wanted to get a voice that sounded like the one from Her." There’s nothing wrong with that.
This whole thing is reminiscent of Valve threatening to sue S2 for allegedly making a similar character. Unsurprisingly, the threats went nowhere.
The voice sounds remarkably like Scarlett Johansson's.