Someone might, of course, use the weak argument that people would learn at what alt contrails started and exploit that knowledge.
So what? I'm sure pilots received weather briefings including the predicted altitude of contrail formation. They would pretty much know that, and can always just look behind them to verify. It's not like they are never going to look behind them, right? It's not like we are talking the secrets of the Enigma Machine.
Besides, if bombers have to fly above that alt, and escorts have to fly up there to escort them, the knowledge is irrelevant. It is what it is.
Of course, the knee jerk reaction is that it could never be implemented and it will never work, or we thought about that back when Bill Clinton was president and decided then no, and can never re-evaluate.
So no, I don't think you will ever get it, but that is different from it being a bad idea. And yes, eye-candy does matter to the market. It has significant weight in the potential customer's evaluation.