One might hope that every "type C" cable will be "PD-aware", but you never really know. On the other hand, the market seems to survive with several variants on HDMI cables (did you want yours to support Ethernet?) and multiple categories of Ethernet cables.

Those wattage numbers are fantastic, though. That's enough to charge most "ultrabook" laptops, if not the bigger gaming models. Certainly, you can see these cables leading to the rapid demise of cheap wall warts for external USB hard drives and other such devices. If we're lucky, they'll make a big logo/branding thing out of future USB 3.1 hubs to make it clear which PD variants they support.