It's not a moot point. Let's say I post child porn on facebook. A cop sees it and I get arrested immediately. Is the post going to magically get taken down? Can cops force me to log into facebook and delete a post? Whatever communication process there is between a cop and facebook, perhaps mediated by a judge, will take some time. In that time, a moderator may have also seen the content, but they aren't allowed to take it down in the proposed system, at least without the appeals going through. The moderator has no idea the person who posted it was arrested - how would they?
And, maybe the child porn isn't actually child porn. Maybe it is totally legal, consenting adults having sex on video, but the adult just looks like a child. Yes, this has actually happened (article in Spanish): https://archive.ph/20140811233956/http://www.eldia.com.ar/ed...
The porn star had to travel to the court to testify that she was 19 during the filming of the scene, otherwise the person may have received 20 years in jail for possessing "child porn". Posting that video on facebook wouldn't be illegal, it would just be against the ToS.