Sayla is Citra's direct ancestor
This thread is more speculation than fact or spoiler.
I reckon, since Ubisoft likes to put links between their Far Cry games, that there might be a reaaally rad link between FC Primal and FC3. Perhaps we'll get to kill a giant, who's head we'll cut off, it'll fall into the sea and form the southern rook island, Like Citra explains in Far Cry 3. That way, Sayla's hero (Takkar) will become the hero Citra is mentioning and mirrors Jason Brody to. Then the wenja will move to the new island and call themselves the rakyat, governed by Sayla's descendants (all the way to Vaas and Citra)
http://i.imgur.com/yT1kjGY.png