Again, paid for by whom?
It won't be a remotely-piloted 777F. It has to be a new creature or there is no advantage.
All those military drones are clean-sheet designs - there wasn't enough advantage gained by automating an OV-10.
The Fedex rumors came from a USAF officer at a conference a couple of years ago. They went viral. But he knew nothing of what he was talking about.
Our main hubs are in huge cities - Newark, Paris, Guangzhao. There will be no remote, thinly populated routes. The first cargo RPV would have to fly into hard weather into Standsted, Frankfurt and LAX. There will be no pass given to cargo.
So, I say again, cost/benefit. Trust me when I say, pilots are an order of magnitude cheaper.
As I tend to do here, let me point out again the number of fellows riding around in the fronts of those big freight trains that go past my house. How long have we had the technology to automate them out of the cab?