This is super interesting.

There are not many cases where one would opt for a radar based sensor over a stereo camera setup. Radar sensors have a notoriously bad azimuth/cross range resolution: It won't be able tell apart your fingers at a few meters distance, let alone recognize your face.

So i don't believe this will be integrated in gameplay features, it would fall short of the original eye-toy for PS2.

They might market this as a privacy preserving feature and enable some other functionality like human presence detection as mentioned in the article.