Please, read this before anything else.
https://theintercept.com/2016/11/29/something-happened-to-ac...
https://theintercept.com/2016/11/29/something-happened-to-ac...
If I would be a user of this service, that's enough of a red flag for me to quit it immediately. Even though I agree that most rumors are blown out of proportion considering the timing.
Looking at the warrant canary and why it might not have been updated, I suppose the most benign explanation is that they're under a "gag order" of some sort. But why? Under what realistic scenario would they be gagged, but not have disclosed user data?