The SuzyQable allows developers, hobbyists, and others to quickly access debugging, recovery, and developer features exposed through some of the USB-C ports on ChromeOS and other Google devices.
To be honest with everyone interested in picking up this cable: is not for the average developer and is recommended for advanced users and professionals.
Internally, the SuzyQable has a 2-port USB hub, and a Rp1A5+RpUSB on the CC pins to activate debug mode. One USB port goes to D+/D-, the other USB port goes to SBU1+SBU2. When you attach it to a supporting port, Google devices enable a USB port on SBU which exposes a bunch of endpoints, including UART (accessible with standard serial drivers) for both the embedded controller and Linux consoles, and, depending on the state of your system, a way to flash firmware using the open-source servod software and flashrom.
Basically, the SuzyQable is designed to replace ServoV2 for the most common use-cases, and uses the same software (unless you just want terminal access, in which case you don't need any software).The USB device the cable talks to gets updates with ChromeOS, so features will be added or changed as development continues.
All ChromeOS devices moving forwards will support this cable, starting with the Acer C101 and Pixelbook. You can find a list of supported devices here