Absolutely, I agree and would like to voice my own content.
I guess it is possible to do it now through a YouTube recording of ones story in our own voice(video not needed).
That could be offered to a reader just under the Medium AI link as a human voice alternative (golly gee the voice of the actual writer, novel idea, snark, snark!)
Yet what a lot of time this would take when it would make more sense for us to read our stuff using Medium's technology.
Then again, what's the big deal about spending more time producing a story when the majority of us basically work for free anyways.
(yup, more snark...)