Another reader mentioned that the 2016 film Fantastic Beasts and Where to Find Them is also listed as 4K and HDR. MacRumors rented the film to check, and we can confirm the film indeed has "4K, HDR" next to it in our iTunes purchase history. Nevertheless, iTunes lists the movie's video quality as 720p.
Back in February Bloomberg reported that Apple was testing a new fifth generation Apple TV that features 4K support and more vivid colors. The new Apple TV is internally codenamed "J105" and could allegedly be released this year.
Then in March, Firi Games co-founder and programmer Tijmen Roberti spotted a new mysterious "AppleTV6,2" model in Phoenix HD's logs. The device was running tvOS 11.
It appears highly likely that we'll soon see 4K HDR content and a new Apple TV device in the near future! Please follow iClarified on Twitter, Facebook, Google+, or RSS for updates.