Apple this morning seeded the first beta of an upcoming tvOS 12.1.2 update to developers for testing purposes, five days after releasing the tvOS 12.1.1 update.
Designed for the fourth and fifth-generation Apple TV models, the new tvOS 12.1.2 developer beta can be downloaded onto the Apple TV via a profile that's installed using Xcode.
tvOS updates have historically been minor in scale, focusing on under-the-hood bug fixes and improvements rather than outward-facing changes. Apple unfortunately provides little to no information on what's included in tvOS updates, so we may not discover anything new after installing the new beta.
Though we don't often know what's included in tvOS updates, we share when new software is available so developers and public beta testers are able to download it upon release.
If there are noticeable changes in the tvOS 12.1.2 beta, we'll update this post with details.