Reasonable bet if they didn't already have root on devices in people's pockets, with cameras pointing at their faces for hours per day. Along with GPS, cell, WiFi and Bluetooth location services.

The video gets deleted, they say. But they don't say what happens to the data derived from that video. Training models and such.

we will learn that they have been using it to gather face recognition data

They already have all that with the trillions and trillions of photos people willingly backed up with Google photos.