Why? Everything here is public information, there's even an API to pull it all down. What purpose would a warrant serve and why would you care?
IP addresses for anonymous commenters/submitters?
Chilling effects are real and I can imagine that there are sometimes comments critical of governments that people only want to post anonymously.
That was my first though, and second one was there should be a centralized place for all the warrant canaries with a simple OK/vanished toggle. I have literally never checked the status of a canary.
Not all info is public: e.g. user email addresses aren't.