Short, simple answer. It will have no effect to the CoS (in terms of the better for the pilot group that is!).
CX will man those fancy jets - whatever it takes. Not, initially at least that is, by improving CoS but by lowering the requirements for new recruits. Any kinds of shortcuts will be taking into consideration (as would/will be with many other carriers). There are, unfortunately that is, still enough guys out there who a desperate to get jobs flying heavy jets (may they wake up someday). Fortunately more than a few are using their experience from CX to go to greener pastures (and yes, they are out there!).