Do we know that these voices are backed by real people? I kind of assumed that given AI tech in voice cloning, they could make a voice sound like anyone they w

Do we know that these voices are backed by real people? I kind of assumed that given AI tech in voice cloning, they could make a voice sound like anyone they want and don't need to go out and find someone that sounds like "the target" voice. I think it's more fair game if they actually found another human that could sound like someone famous, but if they just ran the audio of some of her movies through some AI and out popped a voice, that's a little bit less clear.