This is a circular argument. If the gag orders in question are struck, the canary doesn't do anything: you can just tell people you were served with the court order. But if the canary matters, that means we're dealing with a nondisclosure order that did, at least for the moment, survive strict scrutiny. Since there isn't a legal concept of "super strict scrutiny", that leaves the question of why people believe the canary will fare any better than the objection to the gag order.