I get why this is newsworthy, but I don't get why it's an ethical problem. How is it any different from hiring a really good Bourdain impersonator to read the email? Lots of celebrities have pitch-perfect impersonators; is this a thing we worried about when it wasn't AI doing the impersonation?
Getting away from the specifics of this case, cheap impersonation of arbitrary individuals getting easier raises lots of questions... all those TV spy shows "voice print cloning" stuff becoming more real will make a lot of things involving non-face-to-face trust more interesting.