The official USB Type-C 2.1 specifications have been published, where it is indeed true: USB Type-C 2.1 will deliver a huge 240W of power over a tiny USB-C cable.
In order to pump 240W through that small USB-C cable you're going to need a new USB-C EPR (Extended Power Range) cable, the new EPR specification bumps up the maximum voltage to 48V. This bump to 48V is what is required to push 240W of power at 5A.
USB-C Type 2.1 devices and cables will be backward compatible, and vica versa, with USB Type-C 2.0 ports. Nothing has changed with the port at all, but there are standards on the midplate being stronger, and mandates for pins for A4-A9 and B4-B9 (power, power delivery, and legacy USB 2.0 support) must not short in order to ground during connecting mating.
Until now, USB-C was limited to 100W of power... but the new USB Type-C 2.1 power delivery at up to 240W is through USB-PD EPR exclusively. This is a great move for laptops and high-power devices, as they can shift into a single, standardized USB Type-C 2.1 standard.
Expect this in 2022 and beyond, 240W power delivery over USB Type-C 2.1 is going to be quite a step up.
