Given how much Penn & Teller built their careers on exposing the tricks of other magicians who had guarded their secrets for decades (and getting a lot of stage magicians made at the duo), it's pretty ironic for Teller to now decide he wants government protection for a trick of his.
Disclaimer: esquire.com is not working for me right now so I haven't read the original article yet; I'm basing this on your comment.
They do a couple exposures. Cups and Balls, Blast off, and a new escape in their act that you can choose to cover your eyes for or not.
Cups and Balls and Blast Off aren't exactly carefully guarded secrets... what are you referring to?
They have a particularly gory version of sawing a woman in half for example. I think it is on youtube somewhere, pretty solid.
But yeah, I don't think you could say that they reveal tricks that "belong" to other magicians. They reveal the basic stuff.
— The article.
The Cups and Balls is a classic, and everybody knows, or can easily find out, how it's done. And then they take it and turn that on its head, by doing a routine around "we're going to show you exactly how the trick works, and still amaze you with it". Which is, well, magic.
And in general, a lot of their "exposures" follow that patten. They're much more about artistry and that kind of next-level thing where showing the "secret" doesn't detract from but in fact adds to the effect.