"The core issue with USB-C is confusion: Not every USB-C cable, port, device, and power supply will be compatible, and there are many different combinations to consider." — Total Nightmare: USB-C and Thunderbolt 3, Stephen Foskett http://blog.fosketts.net/2016/10/29/total-nightmare-usb-c-thunderbolt-3/ An interesting and informative article (see link above) that anyone contemplating the use of USB-C might wish to read, or in more than a few cases really should. In example, briefly: "… it gets worse. Many USB-C peripherals are limited in various ways as well. Consider a simple USB-C HDMI adapter: It could implement HDMI over USB 3.0 or it could use Alternate Mode (native) HDMI. It could also use HDMI “multiplexed” with Thunderbolt Alternate Mode or even (theoretically) implement HDMI over Thunderbolt using an off-board graphics chip!" Or, consider that, "If you’re not careful, you can neuter or even damage your devices by using the wrong cable." There is a wealth of specific detail in this article concerning USB-C and Thunderbolt beyond that cited here. On reflection, I foresee world of hurt for Apple in choosing not to provide necessary legacy ports on the MBP for now.