Some consumer wifi company - linksys eero possibly? - some years ago was rolling out a home security feature which used signal differences in the mesh links to detect movement in the house. Not quite 1:1 with mapping, but similar.

There’s been a bunch of “wifi as passive radar” in academic stuff for 10+ years, but w/out the modern image recognition stuff to boost it; most of if lacked public attention due to either academic paywalls or the difficulty of obtaining SDR gear in any affordable way at the time.