When pilot-less happens it would start in freight. No fiery crash with seats full of passengers, just freight lost and that is replaceable. I think the greater threat to freight pilots is the world where you go online to order a product but instead of the company shipping that product you download a single use license to print the product on your 3D printer. That tech exists now and doesn't require coordination with the airspace system and complete security of data to prevent digital hijacking of a plane. Could also severely reduce trucking fleets.