Apple may not have in the iTunes of video content in 4K at the time of the announcement of the Apple TV 4K
According to the source, Apple still has not completed transactions with film studios regarding content in 4K. According to the rumors, September 12, the company has to present including Apple TV 4K (the name is hypothetical).
Of course, for Apple it would be better to at the time of the announcement in the iTunes store was enough relevant content. But, apparently, copertina unable to agree with potential partners on pricing.
The source claims that Apple wants to sell movies in 4K for $ 20. But the Studio allegedly require 5-10 dollars per sale. Yet even it is unclear, whether involved in the negotiations of the Hollywood company.