In regarding the Elon quote, every Tesla has a number of cameras. Tesla the company probably has more recorded video of the roads than anybody else in the world, by a large margin.
The point in TFA is that the roads captured by Tesla are likely correlated to income.
They do, but for what ever reason they are not(or don't appear to be) using it to make machine readable maps.
From what I can work out, they are using the recorded data to create models that can identify road types in realtime, vaguely zero shot. I think musk has an aversion to "HD" maps, which explains a lot.
HD maps would solve a large number of issues for them (its how lyft and wayve do it, well partly. )