Within the facebook post some asked regarding DHs:
Question: "The tales were true... we will get something to do in the prepatch?"
WOW facebook team "Yep! Demon Hunters will have access to the full starting experience and will be fully playable with pre-Legion early access!
Question: "So only the broken isles are offlimits until the 30th' but the rest is playable?"
WOW facebook team "Exactly, the Broken Shore intro will indeed only become available with Legion."
short version: no one was misinformed. Broken Shore will be availabe for every class execpt for DHs. DHs can do broken shore after legion hits live through lorewalker or however they will call the legion version of mops lorewalkers