Earlier quoted context omitted.
I don't think canaries are effective. You can't get around a court order just by mental gymnastics, they'll hold you in contempt. I'd be happy to be proven wrong, but I suspect that they'd simply order you to keep updating the canary.
This would imply that the court can order you to lie to your customers. I think this is not the case. If there is any precedence for any US court requiring public citizen to lie I definitely want to know about it. If the courts are acting like they have this power then it will greatly change my perception of how the courts, NSA, and congress are currently acting.
TL;DR: Judges don't philosophise about specific methods for circumventing their intentions.