There's no reason that they'd add a bunch of new low level content. Ishgard as a starting city would have to be written in a very creative way to tie into the current story line as quickly as possible and not be logically absurd. I really don't see how it could be done without rewriting/ voicing/ animating a lot of the 2.0 story to accommodate adventurers from a completely closed off city which itself plays a part in the story but refuses to supply much aid (or open their borders). It will be odd enough that new players will probably be able to experience that story line while simultaneously having access to the city, though maybe SE will actually keep it locked until you progress far enough.