A He will countermand it and STOP IT
or
B He will tell hostile foreign nations all about it
He is a CLEAR AND PRESENT DANGER to the security of the United States of America
In other words they cannot trust him to shut up and let them do their jobs.
They cannot trust him shut up and NOT inform the ENEMY
He can't be trusted so he isn't in the loop. Isn't that queerly peculiarly interesting?