Hi Everyone, I manage Apple devices and have found a way around this that is very easy to follow along with. For this process ensure your Apple TV is hardlined into your network via ethernet cable rather than rely on wifi as part of the process involves wiping the device.
Traditionally, the steps to add a Apple TV 4k with ethernet involve booting the apple tv up and ensuring it is on the same network as your computer running apple configurator. You then go to Paired Devices in apple configurator and find the Apple TV listed. As we all know, as of tvOS 26.4 and even up to the latest release of 26.6 the AppleTV no longer shows up here.
FIX:
Go through the setupassistant of the Apple TV so you can get to the HomePage.
Update your AppleTV to tvOS 26.6
Next, navigate to Settings > Remotes and Devices > Remote App and Devices
This will now put the Apple TV into a state of looking for nearby devices.
On your Computer with Apple Configurator, launch the software and navigate to Paired Devices. You will now see your Apple TV listed. Select "Pair", enter the code, proceed with preparing.
You will likely get an error and it will tell you it has already been prepared and that you need to wipe the device. Wipe the device. When the wipe is complete and the AppleTV comes back online you will now notice it reappears in Apple Configurator simply as "Apple TV". Select Pair, enter your code, and then right click and prepare.
Congrats. Apple TV is now in ABM, pat yourself on the back.