As I had noted in a prior 5Dx thread, the idea that the 1Dx AF would be in the new 5D3/5Dx was a tough sell from the start. The 1Dx AF and metering (which the new AF is closely joined to) has a dedicated Digic 4 processor in the 1Dx.
That would mean, assuming the approx 7 fps spec is true, if the new 5Dx/5D3 has but a single Digic 5 processor, that one processor needs to handle the 22Mpix x 7fps = 154Mpix, plus all other camera functions. It's taking two Digic 5's to handle the 18Mpix x 12fps = 216Mpix load of the 1Dx, plus all it other functions (not including the AF and metering handled by the Digic 4). The 1Dx has three processors.
If the one Digic 5 can do that estimated load from the 5Dx/5D3, then fine, but if it cannot, I can't see how Canon is going to put 3 Digic processors in a 5Dx/5D3 body, either from the circuit board real estate needed (just look at the 1Dx's circuit board), or just the simple fact that it's putting the same 3 processors in the 1Dx in a body with an estimated price of $2999.
So extending this logic, if you have the same basic guts, a 22Mpix FF sensor, same AF, etc. in the 5Dx/5D3 as the 1Dx, then all you're really getting in the 1Dx is a faster frame rate, dual cards, the built-in grip, and weather sealing for $3800, more than twice the 5Dx/5D3 rumored price. Does that make any sense?
This is why I have never bought the notion that the 5Dx/5D3 would have the same AF as the 1Dx. It does not make sense if you look at the horsepower needed to drive the rumored specs, using the 1Dx's horsepower needs as a reference.
A 1DIV-ish AF seems much more likely and within the realm of 2 Digic 5's. I doubt it's the "same" given the differences in the systems and sensor size, but I can see the same type and technology, along with a couple of improvements learned after the 1DIV's release and field usage.