Are you sure about that date? admin account "u=1"[Date Registered: November 18, 2009, 01:12:33 AM] Has Satoshi created it?
The forum was opened to the public on Nov 22.
I guessed you can blame Bitcointalk's terrible webpage on not having actual reliable sources, you cannot even see BCT links as cited sources for the page. I have read it before that Wikipedia don't count forum posts and links as a reliable source for the web page that is why you can only see others reference links outside of the forum, which is pretty surprising to me as they counted a cointelegraph article as "reliable" source for the page. If they do want an accurate history of Bitcointalk they'll be citing theymos' reply here in your thread.
Yeah, apparently bitcointalk.org links are banned, which is ridiculous.