Jokes on them. I only tried impressions. It's going to make for some pretty funny programmatic scams!
I just saw an incredible Facebook reel of a voice actor, Shelby Young, saying the same thing in a striking range of theatrical voices, and I still wonder. How much of her true vocal fingerprint is unavoidably there?
https://www.youtube.com/watch?v=DyNnyeu_kPU
(As a fan of old movies, "Vintage" was particularly impressive to me -- she is impersonating not just voices but also the choice of tonality those actors made in light of recording technology)
An AI might be able to gain a higher success rate than me.