Do you have any specific examples of devices where this has been implemented? Because I've heard this idea thrown around a lot as a hypothetical, but never any concrete evidence that it's been done.
Hypothetical is beside the point. The hardware is there, the software is closed and you can't verify what is really happening, so the potential threat exists.
https://www.theguardian.com/technology/2010/may/15/google-ad...
https://www.theguardian.com/technology/blog/2011/apr/25/goog...
https://theweek.com/tech/wifi-signals-now-tracking-users-at-...
https://www.youtube.com/watch?v=hlbjUvkoyBA
https://wigle.net/
And here's the opt-out steps to get Google to stop scanning your Wifi: https://support.google.com/maps/answer/1725632#how_opt_out&z...