You haven't purchased any movies on new Apple TV 4k.
I went to watch a movie from my iTunes library today on my Apple TV 4k (latest model), and found my library was empty. I was shown a message stating I had not purchased any movies. However, if I looked up a movie via search that I own, I was given the play (not purchase) option. I tried a full factory reset (with downloading latest update), and nothing has changed. I checked a prior model Apple TV 4k on a different TV, and all library content was present. I also checked the iTunes app on my PC and the Apple TV app on my Mac, and all content was present. This is only broken on the latest model box (which happens to be attached to where I watch the most content).