What they could mean about the battery, is that they are changing the voltage. They updated the 1dx battery, even though it was still compatible with the lp-e4. Canon may just want the new battery for longer lasting life, with the 10fps, and a large file, the camera needs power to save the images.
Something else I'd like, is if canon make a new grip for this 7d ii, I hope it is like the Nikon d300 grip, where you add in a different battery for more power. If they do this with the 1dx battery, and allow the fps to go up, or the fps to last longer, sports/wildlife photographers would really go for that.