This may sound rather pessimistic, but I suspect a 7D Mark II will find its place in the kit of people not wanting to spend a lot of money on a camera body, but who still want to have many pro-camera features, because this is the selling point of the 7D and by replacing it Canon should be aiming at the same kind of target customers.
For me, a 7D is a complement to a 5D - one for reach and speed, one for low-light and image quality. I'll take one of each if they are similar enough in user interface and technology.
But...a 5DIII and a 7DII will probably cost the same as a 1D-x....
And be many times more useful than a 1Dx.
I found it less useful. I had a 7D and a 5D3 I was using, but the 1Dx replaced both. Instead of changing cameras on the sidelines or out in the field, I just kept shooting because the 1Dx did what each of those does and then even more. I realize you need a supertele, but I have several, so that's not an issue. You can't shoot with both cameras at the exact same time, so again, in my opinion, it was less useful.
The 1Dx has the speed, the AF, and the high ISO performance, all in one. Why split it all apart into two different cameras when you can do it in one? That's why a long lens on one, and a short lens on a 2nd one will always be the absolute best scenario. Affordability is another situation.