All I have to say is that if DMC5 does not borrow DmC's level variety, traversal (the floating platforms levels are AMAZING even in subsequent playthroughs!), and at least partially the CC-aspect of some weapons, well... then I will be disappointed.
Following the footsteps of DmC in level design is a must. Doing otherwise would mean DMC still is stuck in RE3-like level mentality.
I think there are plenty of ideas and concepts that mainline DMC should borrow from DmC. I don't find the platforming or travesal a marked improvement at all, personally, but I do think that streamlining the UI in general, and other user oriented features/additions to the shop and training should definitely make it in. I'm also not a fan of the combo pause retained while weapon switching, which is I think what you might be referring to with the CC-aspect?