Intent probably matters a lot here. The actor they hired did not coincidentally have a similar voice. They were hired because they had a similar voice, and the fact that Scarlett Johansson was approached to start with only underscores this.

They were specifically looking for her likeness, for commercial reasons. And when it was denied, they purposely imitated it. That doesn't feel right to me. In the end, they're still trying to use her likeness without permission.

That's different than if they liked a VA's voice and hired them. The voice could be similar, but there was no ill intent nor attempting to copy a likeness. I think they would've been fine if they were even shooting for something like her voice. Where OpenAI fucked up is approaching Johansson to start with, because it shows they didn't want something like her voice or the VA coincidentally sounded similar -- they purposely wanted her likeness, and went behind her back to do it once she denied them.