Here's something interesting....they even tell you up front that you have to progress to a certain point in the story before you can access Heavensward
* In order to enjoy the benefits of early access to Heavensward content, you need to be playing FINAL FANTASY XIV: A Realm Reborn and have made sufficient progress in the main scenario. As such, early access will not be available to new players who pre-order the FINAL FANTASY XIV Online all-in-one bundle and have yet to begin their adventures.
http://na.finalfantasyxiv.com/heavensward/ - it's on the Product page where you see what you get and the prices and such.

So... in all honesty, these new players should pretty much expect to have to do main story before they can access the expansion content.