I'd have guessed to check whether there's anything in the site's capabilities to that could help make this a reality. Like special locks and tools for maintaining and watching debates. It it's viable, it'll go on to being made. No one should go with an idea a proposal that's half-cocked.
Basically what Tyro said. There's no point getting everyone's hopes up if it may not even be possible. Foxy did say he would trial it in the beta-testing forum so everyone could give their opinions.
It is possible. You CAN make a certain subforum accessible only by some members who belong to a group. @see the admin subforum. It is also possible to set a group to be unable to post in a subforum, or only a group to be able to do so. It is definitely possible.
Well the admins have to actually create the group/sub-forum. That's probably why they have to discuss it first. I'm not too sure how it works on the staff's end.
So, you have nothing to fear and the section will likely go to beta testing to iron out kinks to then be rolled out to everypony. No probs. Just a system to make sure stuff works properly.
The real need for testing is if we can put rules in place and have adequate moderators to ensure those rules are followed. Those are the major reasons. If we have people able to join in if they want to like the beta testers, then we don't need to worry about an all site argument, the group committed to the area will be the ones responsible... it might just work. Like I said, needs discussion and testing.