I'm not a lawyer, but my understanding is that warrant canaries work through inaction. If a court were to require the continued publishing of the canary, they'd

I'm not a lawyer, but my understanding is that warrant canaries work through inaction. If a court were to require the continued publishing of the canary, they'd be crossing the line from something approximating a "temporary restriction", to compelled speech. And though I think neither are particularly defensible, the latter is much less so. The key with warrant canaries is that they aren't removing a line from something previously published, but failing to publish an update to to it.