Although, as much as I enjoy the silliness of it, I hope there aren't people that are taking it seriously, the similar "flat earth" joke already backfired.
It seems inconceivable that some modern spy devices aren't camouflaged as flying birds. A perfect smokescreen would be to widely disseminate the patently ridiculous ("joke") claim that all birds are spy devices, thus muddying the waters.
It's a simple logical shift: "there exists" vs. "for all."
Conspiracies about conspiracies, I like it. Wonder how deep we can go.
Claim that no birds are real to hide the fact that some birds aren't real, said unreal birds actually also spray COVID into the air to infect people to convince the population to take a vaccine which contains tracking chips. (110% /s)