IF the 6DM2 had 4K60, or hell, even 4K24, I'd have had to SERIOUSLY consider switching from Nikon to Canon, which would have meant Canon would have sold new lenses, cameras, and accessories. I suspect that I wouldn't have been the only one, either. I've been waiting, and waiting, and waiting, and waiting some more for a DSLR that could do beautiful 4K, have decent dynamic range, excellent high ISO performance, with functional AutoFocus in video and could take stills that would knock your socks off, all on a full-frame sensor, for a reasonable price ($3000 or less). My D800 has served me well since 2012, but it's very long in the tooth. I bought a used GH2 a while back, which was a lot of fun to play with and gave me some pretty exceptional quality video, as long as the lighting was good, but it wasn't what I was looking for. I looked closely at the Sony A7S II, but it has some pretty big issues and it's not exactly a photography powerhouse, not to mention the slim lens selection and all the headaches people experience if they have to service their camera. The GH5 came along and I watched every youtube and vimeo video I could get my eyes on, I read every review that I could find, and decided that it was the camera for me. The GH5's low light is...well, not so great, my D800 blows it away in terms of low light, and it's a 5 year-old camera, but the GH5 produces some of the most beautiful, detailed video I've seen from any camera, and it does all this for less than $2000 AND I can use just about any lens on the planet. I waited until the 6DM2 came out, hoping it would have what I was looking for, because the price would be right. The D850 rumor that it would have an EVF piqued my interest, but when that panned out to not be true, I pulled the trigger on the GH5, I was tired of waiting for Nikon and Canon. And I may still buy the D850, but it will be purely for photography, since Nikon gimped that camera in the video arena too, by not allowing 4K60, or peaking to work in 4K (which is where you need it most). I can't say I'm excited about the features of the D850 though, it's just that I'm due for a new photography camera and the GH5, while taking beautiful images in good light, isn't really useable, for me, beyond ISO 1600.
Canon needs to stop gimping their cameras. Nikon needs to get off their asses and buy, or create a FUNCTIONAL video autofocus, like Canon's Dual Pixel AF (which is one of the reasons I was waiting for the 6DM2 before I purchased the GH5)...there's no better video autofocusing system on this planet than Canon's DPAF. Of course the GH5 has abysmal AF performance too. If I wanted decent AF, my only choices were Canon 5DM4 (bleh) or Sony A6500 and I think the GH5 is a better overall camera than the A6500 by quite a bit and the 5DM4 is a bit of a bear for video (what were you thinking, Canon?!?)
The whole thing is silly. If any of these companies had any brains, whatsoever, they'd make one PERFECT camera, with EVERYTHING that videographers and photographers want and put the other companies out of business. Imagine a D850 with GH5 video specs (and lack of issues like moire/aliasing, along with 4K60, 2K180, 8/10-bit, 400mbps, many codecs, full-sensor readout, etc), Canon's Dual-Pixel AF, flat picture profiles of the Sony A7 line, Dynamic Range of the Black Magic Cameras (along with the ability to shoot to Pro-Res or H.264) and the low light performance of the A7S II, combined with the photography features of the D850 (even at a lower resolution). People would only need ONE camera, for the first time ever. I'd pay $4000-$5000 for that. Of course we'll probably never see a camera that does both photos and video perfectly, because of all the gimping and lack of thought that goes into cameras today.
After owning the GH5 and seeing how much better it is than the GH2, I'm pretty sure that DSLRs are going to go the way of the dodo, not just for video, but for photography, as well. Perhaps not this year, or next, but it will happen. There are so many huge advantages to mirrorless and the only real drawbacks are "full frame aesthetic" (which is mostly nonsense) and low light performance (which is a legitimate concern and one that I share). Unfortunately, for Nikon, which has outright REFUSED to innovate, they will go away when the DSLR does. I've been a Nikon shooter for many years, over a third of my life and I really, REALLY wanted them to succeed, but they're just not doing enough...they just keep throwing out the same stuff, with tiny modifications, but no true innovations. I'd be surprised if Nikon was around in a decade, and a lot of people have already given up on Canon, because of their incessant gimping of their mid and upper range cameras. Canon had such a winner with the 5DM2 and 5DM3, if they'd continued that with the 5DM4, they wouldn't have lost so many customers to mirrorless (primarily Sony and Panasonic), but if you look at the youtubers who have traditionally shot with Canon cameras, almost all of them have gone to mirrorless. Sony is winning, they saw the end of the DSLR over a decade ago. It's just a shame that Nikon can't accept the fact that the DSLR is dying.