I don’t think Apple has publically identified the voice actors and I’m guessing the new voice actors were recorded by Apple with an anonymity clause in their contracts after the first set of voice actors started doing interviews. I don’t think Apple liked that.
Here is a link
It is an article that talks about the people who voice Siri. (although I couldn’t find the name of the American male voice specifically.)
Jon Briggs is the first British male siri
Susan Bennett is the American female siri
Karen Jacobsen is an Australian “GPS girl”
(I know this question was asked almost a year ago, I got bored and started looking at older questions from before I joined)