I would agree that autotune might have kinda change music (although when used in a deliberately exaggerated way it doesn't sound much different from a vocoder), but to me Cher's song is just one of the pop hits that helped popularize the effect. IMO, it's just a very well-produced pop song, which contributed to the rise of a form of vocal processing that's very widespread today, which is already quite a lot. But it's not revolutionary in itself, it's very much in keeping with all the codes of pop music. For the records, I'm actually a teacher in audio engineering at a college and Univ so I've been quite interested in the over-popularity of this type of audio processing in recent decades.

I read a more recent article where they discussed saying that to keep the production trick a secret. I'll have to find the article.

Edit: not the one I was thinking of but here's an article

That 'pitch machine' would turn out to be Auto-Tune, although Taylor would try and keep this a secret in later interviews, stating that it was a Digitech Talker that he'd used to throw people off the scent!

In 1999, he told Sound on Sound: "I played around with the vocals and realised that the vocoder effect could work. I used a Digitech Talker, a reasonably new piece of kit that looks like an old guitar foot pedal, which I suspect is what it was originally designed for. You plug your mic straight into it, and it gives you a vocoder-like effect, but with clarity; it almost sounds like you've got the original voice coming out the other end."

Taylor eventually revealed the truth about the process to The South Bank Show: "I was kind of playing around with the Auto-Tune, as it's called. With this you can shift the vocal, [and] go to to the nearest note. And then what it does is if you bend a note when you're singing, all this does is it goes along and it doesn't bend a note up until it reaches a certain point and then it just flicks to the nearest note, so you end up with these very 'steppy' sounds. Every note is an exact semitone. There is no sliding and that's where you get this crazy sound."