It seems like the key difference is that the advertisements in those cases involved people who sounded like particular musical artists, singing songs that those artists were well-known for singing. If you hired the woman who voiced Sky to say lines that Scarlett had in some of her movies, that would be similar. The fact that this is a chatbot makes it somewhat of an echo of those cases, but it strikes me (a former lawyer) as being a bridge too far. After all, you have to balance Scarlett's rights against the rights of someone who happens to have a voice that sounds like Scarlett's (it would be different if this were someone doing an impersonation of Scarlett, but whose natural voice sounds different).