The portal to Fabled Nizara is missing in Mara in the Village of Shin. There does not appear to be another way to get to it and the zone is needed to complete achievements Heroic: The Fabled Nizara Plunderer Solo: The Fabled Nizara Plunderer
Isn't the server cap at 90? Fabled Nizara is a level 100 zone, so I wouldn't think it would be available until the level cap increases.
The Fabled Nizara, City of the Nayad was introduced with GU101 as part of Fabled Fallen Dynasty, and is not yet available on Kael Drakkel. ~ Kaitheel