They do. They rarely mention it but they do:
https://devstreaming-cdn.apple.com/videos/wwdc/2019/249a0jw9...
The only content regarding audio I saw here are slides 124-140, which cover beam-forming but I didn't see anything about a default beam-forming profile tied to virtual zoom.
On current iPhone Pro (16) you can even select the audio mix you want for recorded video after recording.