I believe the best policy would be to determine your own belief.
Assuming your belief is that gag orders are bullshit and canaries are
stupid games, then:
Inform council you will be taking such position, identify any legal
basis/test such as first amandement / rights.
Wait for warrant, order, NSL, FISA, exigence argument.
Publish it, with/without whatever redactions you see fit, to
whomever/all you see fit.
See what happens.
Nothing better than a stand up fight.
(Never underestimate the power of the 1st).
Now, this is legit advice. FISA would likely wreck you though. The whole design is pretty ripe for corruption. Thing is also, they genuinely believe they're enhancing public safety and all that. If the Commander in Chief thinks this is a good idea, who's to stop democracy from giving the people what they want*?
Reg Canaries, I don't think they work. Why would they? It depends on the phrasing of the gag order, of course, but indirectly saying you got had is still saying it, so I agree with OP's lawyer.
* typically this somehow involves bloodshed, so I guess gag orders are a kindness? Maybe Bill's at the right end. Sometimes I'm so happy I'm not in a lesser democrazy.