Well, the post is only five hours old. I'd say you should give it another 24 hours. If, at that point, there's still not a comment in that thread with a big red

Well, the post is only five hours old. I'd say you should give it another 24 hours. If, at that point, there's still not a comment in that thread with a big red [A], then I agree, that's inexcusable, unless there's some kind of a gag order or other complicated legal thing going on. Heavily-upvoted petitions deserve at least a brief official response. That said, there could be all kinds of reasonable explanations for what happened, including automated anti-abuse defenses that malfunctioned.