Board Thread:Online Discussion/@comment-5031926-20130603014837/@comment-7153552-20130606143235

The quote from Zenimax clearly states that it isn't the Forsworn in ESO, it's their ancestors the Reachmen. They will act somewhat similar in nature to the Forsworn, but with a few distinct differences - I assume your last post is ladden with sarcasm as the Forsworn are terrorists with a reason, and the Reachmen have plenty of reason to attack:

The Reachmen are directly involved in some dark Daedric doings (pardon the alliteration), this allows them the liberty of no reason being a reason to do anything horrible and antagonistic. They're involved in the sacking of the Cyrodil and the Imperial City, plus we're seeing the beginnings of a long-standing fued between them and the Nords. They feel encroached upon and are fighting back, perfectly reasonable given what we know of the Nords and how they treated the Falmer years before this set of events.

As for the what is official and what isn't, what some random person made here on this site for the Forsworn (Online) is riddled with misunderstanding of the long-term lore. Somebody that most likely had only played Skyrim made that page after reading the Q&A on ESO.