The reason they won't have a new starter city:
you can complete everything in this game and see the entire game from 1 character. That's right, 1 character is all you /NEED/ to see everything in this game. They even made the initial story for each starting city only slightly different(maybe play 3 character to 15 pick your favorite and go). To add another starting city that would require an clearly unique story would mean that they would expect battle hardened vets to make a new character so they can see this new content.
Not enough?
the level 15-20 first 3 party instance dungeons is all about the city states and they would need to create a whole new set of starter dungeons or some crazy explanation for how you got dragged into these problems.
The rest of 2.0 story is just more of the smash this new starting city into lore so we can have it be a starting city.
Odds are they will lock players out until x level or x mission in story is complete.