Samsung 55'' 4K Neo QLED TV (2021) support for Apple TV app?
Does the Samsung QE55QN85AATXXC 55-inch 4K Neo QLED TV (2021) has support for the Apple TV app?
This device list does not mention 2021 models: https://www.apple.com/apple-tv-app/devices/
If the list needs updating, then that information would come from Samsung.
The Apple TV app will be either pre-installed or downloadable from the Samsung app repository. If you Search Apps and don’t find it, then it is not available, and not supported for that model TV at this time.