So lets see if I understand this... The 7D2 MIGHT be 21 megapixels, or it MIGHT be 24, or it could possibly be 18. And the 70D MIGHT have one of those sensors.... or it could be something else.....
Yeah, I know... sounds like a company that knows what it is doing, doesn't it?
Actually, it DOES! Really! You don't just crank out a any old new sensor because you have some competition. You prototype, experiment, test a few models, tweak & refine, and eventually produce a solid, stable, final product that consumers will be happy purchasing. Canon had multiple prototype 1D X models out in the field for nearly a year (and quite probably more than a year, if they had them out before the paper announcement) before they finally settled on one. If they are trying to make the 7D line a higher grade professional line, it is NOT surprising if they are testing multiple prototypes with multiple sensor designs.
That said...these ARE just RUMORS. Canon has not actually announced ANYTHING! Regardless of how many rumors people fling about, no one even knows for sure what Canon is actually doing. So, dilbert..you can't really apply the "chaos" you are trying to use AGAINST Canon as their ACTUAL mode of operation, now can you?