The primary reason the USB port is there is to restore the Apple TV to the latest version of tvOS through iTunes if it were to somehow become bricked or otherwise unresponsive.

Mar 17, 2016 My apple TV 4th generation does not have … - Apple Community Sep 03, 2018 Apple TV Q&A (Apple TV FAQ): EveryMac.com

Feb 24, 2016

Mar 17, 2016 My apple TV 4th generation does not have … - Apple Community Sep 03, 2018 Apple TV Q&A (Apple TV FAQ): EveryMac.com

Apple TV is a digital media player and microconsole developed and sold by Apple Inc. It is a small network appliance and entertainment device that can receive digital data for visual and audio content such as music, video, video games, or the screen display of certain other devices, and play it on a connected television set or other video display.. Apple TV is an HDMI-compliant source device.

Networked devices, such as your Mac, PC, and Apple TV, communicate with each other using specific communication channels known as TCP and UDP ports. Learn about the ports used by Apple TV. These network ports are used by Apple TV for communications on your network. TCP port 123 is used to communicate with a network time server.