A quick history of USB
The changeover period
Although the Type-C USB connection is the way forward, there is still a long transitional period until the use of older USB connections become extinct. Many users will have older devices which use the older micro-usb connection, so for the majority, Type-C will only be introduced into their lives when newer devices are bought such as the OnePlus Two, Nexus 5x, Nexus 6, Lumia 950 and the Lumia 950XL.
Expect all new mobile devices to feature the new Type-C port and connection, helping unify the cables and connections used for all device.