Not sure, really. I actually think the 5D4 will be more up my alley. I suspect the same basic ISO performance, but more resolution, and same or better great AF than the 5D3. That will be the camera I go to, possibly. That would afford me the flexibility I really want, without spending a ton of cash.
I think you've made a very good point. If you're not a sports photographer, wildlife photographer, or a journalist/event photographer, then the next iteration of the 5D series will likely fit your needs perfectly. But for those who need the speed, who need the most you can wring out of a Canon sensor, and need the absolute best AF system in the world to capture critically-timed images, then the Canon 1D X Mark II is the weapon of choice for the demanding photographer.