That site typically does not see a lot of traffic on their forums and it is specifically geared toward high school rules. Rules are very similar to most travel ball rules, but there are some differences.
Back in the day, before Arbiter took over the NFHS website, that used to be a fairly busy discussion board. Several of the "usual suspects" who post here on the rules board were frequent contributors. For whatever reason, after NFHS quit hosting this themselves and merged it with the Arbiter website, it seemed to die a slow death.
I checked in there a couple of weeks ago (registered NFHS officials can access complete rule books on the site) and was disappointed to see that there hadn't been any posts on the baseball or softball boards for about four months. Checked again today and still nothing new. I would expect to see a little more activity once the high school season gets closer.