I'm really hoping EF is not dead yet. I have two needs:
Sports: Currently using 1DX, considering upgrade to 1DX2. If mirrorless wants to beat that, it needs to have same-ish AF tracking at minimum, same low-light performance and 10+fps. Hopefully 12-16fps. Dual cards too. I'd be ok with CF although I understand if it's CF+CFast, or further into future 2x Cfast. Neither of the current mirrorless bodies are not even remotely option for these. Also since I'm keying off on action, the EVF delay needs to be stupid low. I think 1DX shutter lag is 60ms? So if EVF has 30ms delay and the body has shutter lag of 30ms, then it'd be equal to 1DX. And typical day is 3k-5k clicks. 1DX can do it on one battery. If mirrorless takes 400-500 on one battery, that'd mean I need 10 batteries. No-go. (+need good ergonomics to hold with 70-200 for a full day)
Other stuff: Currently using 5D4. Mirrorless needs very good ISO100 performance (dynamic range, sharpness etc), enough pixels and probably no AA if possible. Other specs not as critical.
Yes, someday I'm sure mirrorless will be better than my current cameras. But the current mirrorless Canon offerings are pale comparison. So I don't like the plan to kill new EF lenses and concentrate on RF