Where is the list of authorized computers for Apple TV?

Authorization is not specific to Apple TV. It is for all Apple Media Services. It also includes authorization for music, books, audiobooks. Authorization links the computer to a specific Apple ID account for dowloaded protected content. Authorization is specific to computers; it does not apply to other devices.

There is no user-accessible list. You can see how many computers are authorized. You can de-authorize all from any authorized computer. You can de-authorize each computer on that computer (and leave others unchanged). You can re-authorize as you see fit, within the limit of 5 computers.

Removing a device from the list where you are signed in with your Apple ID, does not reduce the list of authorized computers. Those are separate settings.

Authorize or deauthorize your computer for iTunes Store purchases - Apple Support

Do you experience any issues with regards to authorizations?

Apple TV devices aren't listed separately but are included in the following: Check your Apple ID device list to see where you're signed in - Apple Support