It is more complicated than that. Check out Midler v. Ford Motor Co, or Waits V. Frito Lay.
She's allowed to be a voice actor using her real voice.
Your can point to the "Her" tweet, but it's a pretty flimsy argument.
And besides, it sounds more like Rashida Jones anyway. It's clearly not an impersonation.
I'm not making arguments which are not already explicitly written in my post.
My argument is simple: jorvi commented that you can hire "a real-life voice actress" to "try to imitate Scarlett Johansson’s voice as best as she could", and that is not illegal.
I said that the legality of that is more complicated. What jorvi describes might or might not be illegal based on various factors. And I pointed them towards the two references to support my argument.
I explicitly didn't say in that comment anything about the OpenAI/ScarJo case. You are reacting as if you think that I have some opinion about it. You are wrong, and it would be better if you would not try to guess my state of mind. If I have some opinion about something you will know because I will explicitly state it.