I expect the existing laws will be extended. I had a colleague tell me about looking into how much Morgan freeman wanted for a 15s commercial ($$$$$$). The alternative he used was a “sound alike” voice actor, for which Morgan Freeman received royalties to the tune of $$$$$.
It's a neat demo. I don't know how I feed about cloning the voice of a living person, even a 'public' figure like a presenter. I wouldn't be surprised if it eventually becomes illegal, although it'll likely be as difficult to enforce as normal casual copyright infringement.