Apps & Software
YouTube won’t be supporting its app on the third-generation Apple TV
The change takes place early March.

YouTube is soon to stop supporting its YouTube app on the third-generation Apple TV models. Now, users will require AirPlay to start a video playback on other Apple devices to view content on the Apple TV.
The discontinuation is applicable only to the third-generation Apple TV and is set to take place in early March, as reported by 9to5Mac. However, you can watch YouTube on Apple TV HD and Apple TV 4K like usual as these devices run tvOS with a built-in App Store.
Following is the message being shown to users:
Starting early March, the YouTube app will no longer be available on Apple TV (3rd generation). You can still watch YouTube on Apple TV 4K, Apple TV HD, iPhone, or iPad. With AirPlay, you can also stream YouTube from your iOS device directly to any Apple TV (3rd generation or later).
As of now, YouTube has been available as a channel option for Apple TV users.