In the UK Apple Store, there are some films that are apparently already prepared for Apple TV soon but then times the jump in the direction 4K daring. We had and expected more, but we have always been disappointed in this respect.
Various purchases are probably in the bill (previously only in the UK shop) as “Movie (4K, HDR)”, but are not yet loadable in this quality.
Of course, this seems to be more like an oversight, but it seems quite a while that it is only a matter of time until the new Apple TV also introduces 4K and HDR as options, even if no major innovations from Apple TV Are expected.