If it leads to many more banners flying around in the sky or if they are allowed to fly closer to the ground (thus being more intrusive) then that's a bad thing. But if they simply replace banners towed by small, piloted aircraft, then that's a good thing because, 1) drones use electricity instead of gas, which is better for the climate; 2) those damn airplanes make a bunch of noise pollution, which would go away with the drones.
But yeah, if it leads to more intrusion, that's not good.
Personally, if I had a choice and could choose to get rid of all the ads on the internet and instead have a silent banner fly by in the sky occasionally, I'd take the latter.