I'm not a lawyer, but that's a double-edged sword because then the feds would be opening up questions about the constitutionality of the gag order in the first

I'm not a lawyer, but that's a double-edged sword because then the feds would be opening up questions about the constitutionality of the gag order in the first place. These secret national security warrants are still a thing in part because nobody has successfully challenged them in court. It's possible that if the government wants to argue that taking down a warrant canary constitutes violation of the gag order, the court could ultimately rule that the gag order itself is an unconstitutional prior restraint on constitutionally protected free speech.