Apple has today released tvOS 27 for Apple TV 4K (2nd generation and later).
According to Apple, tvOS 27 includes support for larger accessibility text sizes, high-resolution lossless audio in Apple Music, and a redesigned Podcasts app. More details should become available in the near future when Apple updates its "About Apple TV 4K and Apple TV HD software updates" Apple Support document.
Unfortunately, we were not able to test tvOS 27 during the beta cycle; and thus we do not have any information on whether this release contains any changes to vision accessibility features beyond the added support for larger text sizes. If you have upgraded to tvOS 27, we would greatly appreciate hearing your experiences with the update.
To install tvOS 27, go to the Settings channel, then look for the System section near the bottom. From here, look for Software Updates under Maintenance, then select Update Software and Download and Install. Wait for your Apple TV to download the update. Don't disconnect or unplug your Apple TV until the update completes.