There is a voice mode in the GPT app that's been out (even for free users) for nearly a year now. There are a couple voices to chooses from and sky was one of them.

This mode works entirely differently from what Open AI demoed a few days ago (the new voice mode) but both seem to utilize the same base sky voice. All this uproar is from the demos of new sky which sounds like old sky but is a lot more emotive, laughs, a bit flirty etc.