Could a voice changer like that be made...

no.

that voice changer thing was BS.. even in 2000

I got one that makes me sound like Morgan Freeman, sonny. And one thing about changing your voice that I'll always hold true to - it doesn't change your soul. Funny story that I'll never forget from the local lemonade stand owner who set up shop on the banks of the Ogrechobee river down Yutterby way when I was knee-high to a jockey. He said the world will turn you on your head, if you let it, and all you'll get is ruptured blood vessels in your eyes for your pains.

this movie is over 20 years old and that technology still doesn't exist.

Yes it could be made.

No.