No. I've talked to lawyers in a non-client capacity and they all agreed that taking down a warrant canary after receiving a NSL would probably be viewed as equivalent to a straightforward disclosure, since you deliberately put yourself in that situation. There is no relevant case law that I am aware of.
In the early part of the 20th century, the Automobile Association (the "AA") would send 'scouts' out to find speedtraps and warn motorists to slow down before arriving at them. Within a few years cops got fed up of not catching speeders, it was decided in the courts that warning people about speedtraps was an obstruction of justice, and therefore illegal.
So that put an end to that game, right? Nope. The AA developed a new technique. Their scouts would salute all passing cars at all times... unless something was wrong.
If the AA scout didn't salute you, you knew there was a speedtrap.
The theory here was that the law could not compel an AA scout to salute motorists. This worked for about 50 years, until the practice of warning motorists of speed traps (or perhaps rather, not signaling to them an absence of speed traps...) was discontinued for road safety reasons (basically they decided that speeding wasn't a brilliant idea).
http://www.theaa.com/aboutaa/history.html
http://en.wikipedia.org/wiki/The_Automobile_Association#Hist...
So basically, while "Judges don't take kindly to tricks" does make a certain amount of intuitive cynical sense, if we remove computers from the equation (our intuition on morality/ethics seems inconsistent when computers are involved for some reason), does it seem reasonable that a judge might compel a free civilian in a free society to salute? Of course not.
I wonder why they decided that. Speed traps have nothing to do with improving road safety. In fact they often make roads more dangerous if they expect you to slam on the brakes.
For whatever it is worth, it seems they still provide some speed trap related services: http://www.theaa.com/apps/safety-cam-iphone-app.html
It’s not as clear as an explicit sign (in whatever form) being taken down. The interpretation is much more difficult and vague (also to observers like us who would be the target audience for such a canary): Did they just forget to include this language this year or did they actually receive a request? It also requires actively doing something (including the language in the new report) instead of doing nothing (not taking down the sign).
This is very vague as you can see by the many people here doubting that this is a canary at all. If it is indeed one this might afford it legality.
This is the crux of the problem. If we assume Apple is being truthful in its statement, they should be completely free to make such statements. No-one should be punished retrospectively for statements that were true at the time of utterance.
Compelling someone to lie after the facts have changed seems to me a far murkier legal area (and perhaps easier to fight in court).
And IIRC C-level executives are required to certify they believe their quarterly reports are, to the best of their knowledge, accurate, under Sarbanes-Oxley. There is a ticking clock here, once Apple asserts that the nebulous statement is relevant to the value of the company, because some customers are tetchy about their data.