So the 6Dii is a 6D with a flippy screen. 2 x product lifecycles (around 8 years) and that's progress at Canon.
It's baffling.
Not that baffling. As I said before, Canon will wring out everything out of it's fabrication lines and other technology until they decide it's time to move on. The only thing that gets regular upgrades are the digic processors.
As an 80D, 5D mark iv, and C100 mark II owner, I no longer trust Canon to come out with any single product that excites me... in fact I now only trust them to screw me over.
Trust is everything to a brand, and once lost its very difficult to win it back.
Let me give you some examples...
1) My C100 mark II has been a great tool for my video work, but its well marketed dual pixel auto focus with face detection only works with 3 or 4 cheap zoom lenses. Canon have not updated the firmware for it to work with any other lenses.
Most Canon Camera's are capable of a lot more through the digic processors, it's just that they intentionally cripple a camera to reduce functionality. The Magic Lantern peeps have shown what's possible. Though they haven't looked at the C100 MKII. Canon's firmware updates are few and far between. I think the last major update was for the 7D to get more life out of it before they released the 7D MKII.
2) The 5D Mark IV has the auto focus the C100 should've had (it works with all lenses), but has a deliberately crippled HDMI output (no 4K), a cropped and crippled 4K codec (Motion jpeg) that is all but unusable in the real world, and no flippy screen.
Well that's what Canon do, they develop an AF module for the 1D series usually then it works it's way down the range in different configurations. As far as flippy screens go ? You likely won't see them on the Professional Cameras anytime soon, as Canon can't as yet dust seal the camera's properly.
3) The 80D has the flippy screen and the autofocus skills, but being a crop sensor suffers in low light.
It's a trade off, the 80D sounds like it's good for wildlife photography on the AF front (as it was on the 70D). I will upgrade to Full Frame eventually, but I won't be ditching crop sensors. They have certain advantages over FF in some situations.
So Canon put a flippy screen on the full frame 6Dii, but being Canon had to make sure some area of its performance was crippled, so they screwed up the dynamic range (which is better on the cheaper 80D).
That's what most manufacturers do, they cripple features through firmware to encourage people to buy a higher priced model. What the 6D MKII will do is likely drive sales of the 5D3 and 4 for those who've can afford to spend a bit more.
They just don't want you to have what you need at prices that exceed more capable competition.
Well it's partly that and Canon's habit of wringing out as much profit out of it's fabrication processes before they will commit the cash to upgrade them. If they ever do match Sony's sensor performance it will appear in the 1D series first, then the 5D etc. So it's a matter of waiting for Canon to announce investment in their fabrication factories.
I've stuck with Canon and built up my lens portfolio and accessories mistakenly believing that they were 'taking the time' to develop the one camera that really competes... but it is blindingly obvious they won't be doing that...they believe in taking your money and kicking you in the shins on the way out.
Sony do the same on the lens front, they produce great Cameras but they are behind on lenses. Sure they are producing some high end lenses but they simply don't have the depth and range that Nikon and Canon do to compete on a level playing field. Third Party lens makers don't appear too interested in Sony Camera's at the moment as they have to reverse engineer the lens mounts.
Canon has been far more interested in expanding it's other business interests in recent years than the camera side of things. Which is a sensible thing for them to do, given how the Camera market is going. We are back to where we were in the film days, the masses are going for camera phones that offer instant results, while those who are serious about photography will gravitate towards Cameras in DSLR, Mirrorless and for those with the cash Medium Format.
I may go for a Sony FF camera with an adaptor for my EF lenses. I only want FF for the low light performance, I think I'll stick to crop sensors for wildlife however.