I dunno. I doubt it is. But I also doubt there isn’t something they are getting back.
Maybe not personal information but I’d imagine there will be data on what keywords it flagged on and whether the user hung up or carried on with the call etc. They wouldn’t be able to fix or improve the service without getting information back.

They said the AI stuff is all done on device so nothing is being sent back to Google

Sticking with duck duck go. Not seeing advertising, news or video recommendations based on a one time search in Google is bliss.