I don't think it's less malicious if they decided to copy her voice without her consent, but just didn't tell her until the project was underway, then continued even after she said no.
There's legal precedent that hiring a copycat is not OK, so it's not like proving it was a copycat salvages their situation.
I wouldn't be surprised if the real reason they hired a copycat early is because they realized they'd need far more of Johansson's time than she'd be willing to provide, and the plan was typical SV "ask forgiveness not permission, but do it anyway regardless."
That doesn't matter because it's an impersonation. Ford lost, even though they didn't use Bette Midler's voice either: https://en.wikipedia.org/wiki/Midler_v._Ford_Motor_Co.
"We believe that AI voices should not deliberately mimic a celebrity's distinctive voice — Sky's voice is not an imitation of Scarlett Johansson but belongs to a different professional actress using *her own natural speaking voice*"
If you listen to the imitation version linked from that Wikipedia article and the original 1958 you'll hear that they didn't only find a singer that sounded like her, but copied the music and cadence from Bette's version.
I think that's way past what whatever OpenAI did in this case. It would be analogous if they were publishing something that only regurgitated lines Scarlett Johansson is famous for having said in her movies.
But they're not doing that, they just found a person who sounds like Scarlett Johansson.
This would only be analogous to the Ford case if the cover artist in that case was forbidden from releasing any music, including original works, because her singing voice could be confused with Bette Midler's.
Now, would they have done this if Scarlett Johansson wasn't famous? No, but we also wouldn't have had a hundred grunge bands with singers playing up their resemblance to Kurt Cobain if Nirvana had never existed.
So wherever this case lands (likely in a boring private settlement) it's clearly in more of a gray area than the Ford case.
Same way you can't get someone who sounds like a famous celebrity to do voice in a commercial and just let people think it's the famous celebrity when it's not