The IGFA’s International Angling Rules state that “Outriggers, downriggers, spreader bars and kites are permitted to be used provided that the actual fishing line is attached to the snap or other release device, either directly or with some other material. The leader or double line may not be connected to the release mechanism either directly or with the use of a connecting device.”
While the rules do not specifically mention the use of drones, the same intent of the rules quoted above applies. As long as the mainline is attached to a release clip that allows it to separate away from the apparatus (in this case, a drone) once the fish strikes, this technique would be IGFA-legal as the device does not give the angler an unfair advantage with fighting the fish.