Was there ever an Xfinity Stream app in the App Store for an Apple TV? Maybe your model isn't supported. Doing a search in this Forum for 'Apple TV' this thread shows up: https://forums.xfinity.com/t5/XFINITY-Stream-Website/Re-Apple-TV-Xfinity-streaming/m-p/3189291#M8200...
Hello I have tired to install the stream app on my Apple TV and it’s not in the App Store. However when I look for it in my IPhone it’s there. Did Xfinity take it away from Apple TV now?
Thank you for posting your question here in the Xfinity Forum. Currently, the Xfinity Stream app is compatible with the following Apple devices and operating systems.
Supported Operating Systems
To find and download the Xfinity Stream app in the Apple App Store, your device must be running iOS 11.0 or later. AirPlay is not supported.
Supported Xfinity Stream App Versions
To access and watch all content, including content available to watch when out-of-home, Xfinity Stream app version 4.1
If this changes, we will be sure to provide those updates here: https://www.xfinity.com/support/articles/xfinity-tv-app-requirements