Apple has released the first official update for tvOS 12 in the form of a beta to developers registered in Apple's beta program. This release comes days after the public release of tvOS 12 and likely aims to address any issues or bugs that have been brought to Apple's attention after the public release.
Apple's tvOS updates have historically been minor in scale, and the company rarely provides detailed changelogs with new software releases. We will update this post if any new features in tvOS 12.1 are uncovered during testing.
Developers can download the latest tvOS beta by heading to developer.apple.com or as an OTA update directly on their registered devices by heading to the Settings section on that device.