the canary notification method is a lack of updates, not a specific update.

you update your canary to say that nothing has changed, at a known cadence.

if you ever dont make the update, readers know that the canary has expired, and so you have been served a gag order warrant.

changing or removing the canary in response to a warrant is illegal. not changing it is legal.

for an equivalent cloudwatch setup, its checking the flag for "alarm when there's no points"

>Warrant canaries depend on action, the removal or altering of the canary document.

No, they can simply not publish a warrant canary in the future, which will tip people off if they've been publishing it regularly in the past.

In all likelihood there's just language like "to the extent permitted by law", which The Guardian isn't telling us about. Even if they didn't write that explicitly, it's implied anyway - Israel knows any US court would void any provision requiring Google/Amazon to commit criminal acts (illegality doctrine). It's also not really possible for Israel to be break laws of foreign states, since it's not bound by them in the first place.