"better vehicles for greenwashing"
If Canberra has less high rise towers than Sydney, that might justify trialling the drones in Canberra. Towers inevitably create wind currents that can be finicky, and I don't think we have the coding chops to ensure that drones navigate through turbulence safely.
But apart from that, Canberra also has plenty of sunshine if I'm not mistaken. The drones can almost certainly be recharged by solar power, which would mean that they only cost maintenance, not energy.
I have no idea if this is fact, but it is plausible.
I'll have a tin of caviar and a bottle of champagne for delivery . . .