Personally I see that the new AF system seems to be very powerful and we haven't seen it's true potential yet.... eventually jump to R, but only when I see a killer feature/spec ...
We will see it with a 5D4 successor in the R system (?) or an 1DX2 equivalent body.
Until then my only true question is if there will be a 5D5 or if Canon will evolve the R system so fast, that the EOS D / EF system is already about to die.
Future will tell and it will be an interseting one.