That's what I have been saying all along. If you watch the videos documenting the work at DLR, you will see that they are building literally from the ground up there. A lot of what they were doing this past winter was just getting massive electrical, water, and sewer systems extended out to the middle of nowhere. You can actually go back and watch them bury the main electrical switch box or whatever it's called (sorry, I'm not really well versed in electrical equipment), and the pipes that run it all around.
I certainly wouldn't bet on anything yet, but I know their goal must be to get them to open simultaneously. Or, at least create that perception. Perhaps DLR will actually soft open earlier, like Pandora did, only a few months instead of weeks. But I'm pretty confident that come hell or high water, they intend on publicizing a nation-wide release date. This is an absolutely golden opportunity for them to be able to market both resorts together, not to mention prevent massive guest confusion and disappointment.