Hardly, or half the posts would be gone :-)
What we do moderate is posts where one person harasses another. This happens only rarely, except we had a recent large volume of such coming from a Tor node. So posts coming from the Tor node need approval from one of the moderators for the time being (until that person goes away).
You can also use the NNTP interface to access the forums, which doesn't moderate in advance (that only happens if you use the web interface to post).
The web forum software is a shell around the NNTP interface. It's a bit difficult to make a HackerNews/Reddit style moderation system work on it because of the way NNTP works.