"For reasons of national security" is just a blanket excuse for secrecy. It may or may not be the real reason.
Personally, I don't believe that the "tic tacs," etc were ever the result of any sort of leak or that there was ever any "disclosure" intention. UFO info and other such "outside the bubble" topics have always been classified and will always remain so. The phony leaks and disclosure claims are just to placate the masses. The world works a certain way and any information that might upset that structure will never be made public. (My opinion).