Yup provided it is in a seperate disc but they can't do that unless they sell the physical bundled game on launch since HW is included. I believe the topic starter bought the digital copy which is the only one available right now and Heavensward data is compiled in there. Not unless Square Enix lock Ishgard and all that new content away till launch date while letting players access ARR content for whoever bought the bundle then it is possible for them to play current content first.