-as always there will be-
As I heard suggested recently,
No longer will ANYONE believe, "we're hijacking this plane to [Cuba, Winnemucca ...]". Unless they have serious firepower and not just knives - nobody in an airplane anywhere in the world will ever again remain spam-in-a-can.
Memories (or imaginations will do as well) of the Pennsylvania crash will lend courage - swarm quickly and you might even get out alive.
So plugging THAT loophole over and over .. betrays the unimaginitive minds that an admin such as this one Would employ. Let's be "Conservative" and plan for the Last One.