[Ukv]

Could work for spear-phishing, or impersonating a widely-known trusted figure. I can't really see it working for cold-calls that pretend to be someone the victim knows (like the terrifying ransom calls), since the operations work at a huge scale expecting most people to not even pick up a "scam likely" call. Even if model tuning is free and instant, just having to find a voice clip of the person prior to each unanswered automated call would tank the quantity they're able to make.

Though, for the same reason websites always attribute data breaches to a "highly sophisticated targetted attack", I imagine there will be some unevidenced claims that this is what scammers did to them - people don't want to have been fooled by something simple.