Love the work... Looks like he's in chartered helicopters/light aircraft, not flying a drone, so I can't see how this would be any more irresponsible than any other flight.
In the case of Arthus-Bertrand, in at least some cases he used ultra-lights. I remember a series in Photo over a central asian desert, where one shot included the shadow of his UL. It was small enough that they could cart it in using a 4WD, then assemble it on-site.