Whether the MPL will become the norm remains to be seen. It may well produce good FOs who can follow SOPs and operate modern glass cockpit aircraft efficiently but will they make good captains? Will they be able to make good comand decisions when required? Time will tell.
I can't see the traditional CPL/multi IR route disappearing for a long time, if ever. Small airlines and GA operators just won't have the time/money to train MPL students, particulary as those they recruit may only be there for 1-2 years before moving on.