I think this would be a game changer IF it comes in under $2.5k.
It almost certainly will not be that cheap. I'd expect a camera that's billed as a 'mini 1D X' to be priced in the $3500-$4000 range.
That sounds about right on the price. Although it really depends on features. If it has new sensor tech that is very impressive, I could see it coming in over $4k. Rehash of the same sensor technology, but with 1DX AF system, great weather sealing, maybe 24 MP, then ~$3k.
From a structure standpoint it would put the 5DIII and the 7DII beneath the 1Dx at about the same price point with the 5DIII being FF aimed at event and portrait photographers and the 7DII being aimed at sport/wildlife photographers.
I don't feel that distinction will be possible any more with the 5DIII having a decent burst rate and excellent AF system. When Canon had 1DIV and 5DII as the second tier below 1DsIII, then 5DII aimed at event and portrait and 1DIV aimed at sports/wildlife made sense. But now, people will probably not favor a 1.6 crop priced higher if they can get the 5DIII to work for sports/wildlife reasonably while being excellent for event/portrait, all the time being cheaper.
There are both pros and cons of the 7DII being a mini-1Dx to me, the former involving better ergonomics and the latter mostly involving size/weight and price. However, if 70D fills the niche of an advanced general-purpose APS-C body and pushes 7DII to a pro body exclusively for sports and wildlife, I am fine with that. All I care about is the current 7D setup (all of it) with good performance at high ISOs.
Except, it feels like a step backwards- what will Canon achieve with a low-light capable, excellent AF, fast frame-rate APS-C body- didn't they have all that in an APS-H body in the 1DIV already? What can be gained additionally other than the ability to use EF-S lenses?