Again, assuming only sensor tech matters. The 1D X and 5D III are phenomenal cameras for the market niches they are intended to fill. They have EXCELLENT IQ, even without two extra stops of DR, but sensor isn't necessarily the most important technology factor. There are gobs of other technological improvements in those cameras as well, not to mention they are all full frame.
So, the 7D II comes along with new sensor tech...its APS-C! It isn't going to be encroaching on 1D X nor 5D III territory any time soon...its a different class of tool for a different market...even IF it has better DR, same 61pt AF system, 10fps frame rate, deep frame buffer, rugged body build, dual CF cards, and comes strait out the gate with all the other improvements added to the 1D X and 5D III with firmware updates: f/8 AF, blinking red AF points in darker conditions, etc.
The big MP camera is, once again, a different beast. I fully expect it to be KILLER on the IQ front, including at least two more stops of DR. If it isn't, it's a dud on arrival, as there is no question the market will compare it to the D800 and Sony Exmor. It'll be a BIG MP camera, though...so it won't be taking on either the 1D X nor 5D III. It'll have a low frame rate. It'll probably top out at ISO 26500, although I wouldn't be surprised if it topped out at ISO 12800 (with great quality). I suspect it won't have a deep frame buffer. As a likely studio camera, it could very well come with an integrated grip, and be 1-series, although I wouldn't really be surprised if its a new 3-series camera. It will serve an entirely different market than the 1D X and 5D III, most likely at a price point somewhere between the two.
So, the 1D X and 5D III have their place, for at least another three years. I see no reason for anyone to be worried about their purchase, or even planned purchases, unless they are a bird & wildlife photographer, landscape photographer, or studio photographer (in which case, waiting for the 7D II or Big MP only seems logical.)