This must be an opt-in. If people aren't bothered enough to make time to sit down, read and think about the stuff I write, then they needn't bother!
Also, if this abomination does take place, I demand the right to choose the voice my articles are heard in. I do not want some US- or mid-Atlantic accented bot mangling my particularly English English, thank you!
If this was to be a service to visually-impaired readers, then that would be fine, with the above provisos. But I do not want my work spoon-fed to the intellectually lazy!