The dangerous part is that it sounds like the ad is generated by Spotify.
In the “tech already exists” scenario, an advertising firm will have to guess at the voice people want to hear and submit their own audio files to advertise.
If this works the way it sounds, the ad firm sends in some text and Spotify generates a voice ad based on who you listen to. Less effort on the advertising firm and far more targeted.
Both are bad. The second is worse!
And frankly, it’s another reason not to support Spotify. You are supposed to be paying to listen to music, not support research into this bullshit advertising.