I've gone through a successful installation of the tvOS 16 Beta profile on an Apple TV 4K (2nd Gen). Apple TV 4K reboots after the install. Yet, when I go into the System settings to have it look for a software update to download tvOS 16 Beta, the device says it is up to date.
I have the same issue too, I’ve tried on multiple apple TV’s in my house and got the same issue.
Same issue here.
I just found the solution on Reddit: Make sure you have 'Get Beta Updates' set to off, in the Apple TV settings. Once you turn this setting off the TvOS 16 beta will appear after selecting system update.
This is completely unintuitive, but it works!
I can confirm that "Donovan's" solution "Make sure you have 'Get Beta Updates' set to off, in the Apple TV settings. Once you turn this setting off the TvOS 16 beta will appear after selecting system update" works like a charm.. and yea.... how dumb is that!