Just to clarify this is not regular multi-mode fiber, but a single fiber with seven cores.

A singlemode fiber is limited to about 100 Tbps per fiber at 10 bits/s/Hz. It is not obvious to me how much bandwidth usage has to grow until it becomes more economical to deploy this new kind of fiber rather than multiple (existing) singlemode fibers. For example, for high bandwidth applications MPO connectors with 12 or 24 fibers per connectors are used.