From the article:
"Once they hit the end of their adventures in Timorous Deep, new Kunark players will then have a chance to blend in with the rest of Norrath. The rest of the Rise of Kunark expansion is based on levels 65 and higher. That means sailing out via the docks in Gorowyn and leveling up the rest of the way in the preexisting zones from 20 to 65. When players return to Kunark, they'll enter into the Kylong Plains..."