Sorry, I don’t buy it. I think the redacted product is Siri, and the author’s dismissal of this possibility shows how people underestimate the number of voice searches conducted using that service. As far as I know, it is the world’s most-used “AI service.”
I took a look at the PDF linked from the Register article but sadly the term is replaced with an icon in reflowed text, rather than a black bar, so you can't judge the width of it to tell which term is more likely.
I agree Siri would make sense, but on the other hand I can't imagine any reason Siri would be redacted.