So the Military is going to take away their pension if they tell what they saw? On what basis? Sorry; not buying it.
They're the military, they don't need a "basis." Something you see is now suddenly classified top secret, they don't have to tell you why, and they don't need your agreement. It's now top secret, and they tell you to shut up. If they're in a good mood, they make up a story about a new weapon system that is crucial but malfunctioned and has to be protected from bad press. If they're not in a good mood, they don't tell you anything. The point is that once it goes into the classified system, if you violate it, your trial will be classified, too. It all depends on how serious they want to be, but yes indeed they can do it to as many people as they want, and they do keep a database on who's been warned.