if you would like to autofill the form anyway click"
i made it a little terse, but there has to be a way to make it succinct and human readable.
But I think in general, some kind of prompt or override would work. I absolutely agree that if a user wants to use the browser autocomplete functionality, they should have an option to do so. I have no understanding for websites that just want to disable autocomplete without replacement.
However the concerns seemed to be about autocomplete being incorrect or conflicting with application-provided lists. I can see how that leads to frustration and confusion with users.
The Chrome team seems to trust its algorithm to an amount where they don't seem to find it necessary to deal with incorrect results - a view which doesn't match reality apparently.