I would assume that unless you are able to deliver enough power to damage the receiver (and remember it goes down fast, r^2, plus transmitter is on the side of the microwave, standing wave perpendicular to the door), it wouldn't really impact transmission. It's not AM radio and you are not even outputting noise with timing comparable to transmission, just adding constant (or maybe 50hz sine).
Plus there are multiple channels at 2.4Ghz, and you are probably outputting a narrow single freq.
But that's just me guessing, I'd love to know if it would actually work.
It slightly changes frequency randomly on every zero crossing of the input frequency, so 100Hz FSK modulation effectively. It is enough to slow down your bluetooth and wifi when the door is closed and the radiated power is fully legal (<0.1W IIRC), so the effect should be amplified a lot when the door is open. Long distance flight is already getting close to the limits of what signal integrity you can get, so even a few miliwatts at the drone might be enough to disable the communications with it.
I too would really like to know, and try it too, but getting permission for 800W transmission would be a pain.
In the us the regulations say "minimum power required" but no more than 1W eirp, which means the radio can be less than a watt with a directional antenna.
Good 802.11 radios can do 1000mW.
A microwave oven magnetron and a simple aluminum waveguide is many hundreds or thousands of times more effective radiated power.
Plus there are multiple channels at 2.4Ghz, and you are probably outputting a narrow single freq.
But that's just me guessing, I'd love to know if it would actually work.