This is cool and impressive:
In particular I liked how they added human imperfections to make the calls sound more natural and flow better. I can already see the applications, although I suspect they are more on the service provider side than on the consumer side. Restaurants answering their phones etc. Or telling your washing machine what to do; Alexa on steroids.
There's also some potential for misuse in robocalls, real-world denial-of-service (call all hairdressers in the country and make a reservation), and spam/scams.
(When will AI research result in a reduction of human labour on repetitive and inhuman tasks, like participating in conference calls?)