Get this straight. There will never be a Canon DSLR or mirrorless model with 'better video capabilities'. What was a suspicion earlier is now confirmed. If you are looking for serious video look to other brands.
Unfortunately, this could be right. Canon would rather leave hybrid stills/video money on the table than cannibalize. Of course, the other guy could be right, too, that they just don't have the sensor tech for efficient FF 4K video, let alone 4K 60p, but I find that hard to believe. The 1DXII has it.