Except when they do, like half of what Legion was? Like what all of Pandaria was? (Originally Pandaria was a small island believed to be west of Stonetalon) Thunder Isle? Deepholme? Stormheim?
They're fully able to turn Tel'Abim, or any small island or chain of islands into a continent if they felt like it,
because its already happened 3 goddamn times. They can make up new continents on the spot, because they already have, and can do so again.
BTW, here is the map of Chronicle Vol. 1
Gee, I wonder where the hell the large, 3-zoned continent of Kul'Tiras is on this map?
You mean, that small island in Baradin Bay??