Probably the least unhinged theory in this thread, but unfortunately it doesn't make a lot of sense to me. If they had intel about such a threat, they'd have to move all high value assets to another base pronto. A flight ban won't stop a shady box truck from rolling into town and releasing a swarm of small drones.

(It would also be uncharacteristic of Iran to actually attack America directly, on American soil. Try to find examples of Iran doing that and you'll come up quiet short.)