I think the article gets network slicing wrong. Using network slicing instead of the traffic shaping that the mobile edge router probably supports is a strange idea. The showcase network slicing use case was public safety comms. Network slicing is AFAIK not much used because it clashes with roaming. The article describes network slicing as reserving spectrum for certain apps. That's not how it works. It reserves capacity.

Still, zero-rating and traffic shaping should not be used to favor apps, especially not on a pay to play basis, for all the same net neutrality arguments as ever.