Microsoft has told Eurogamer that Primetime will not be a part of the New Xbox Experience on November 19. Other features may also be absent, although there's currently no word on which ones may not be live on launch day.
"The New Xbox Experience is a long-term initiative, and what we are rolling out on November 19 is only the beginning," said a spokesperson.
"With the New Xbox Experience we will have the flexibility to roll out features and updates dynamically, unlike in the past where we were on a more biannual schedule. So, there are a lot more exciting features, including Primetime, that will be coming soon."
Early estimates put the Primetime feature as a spring 2009 release, according to Forbes.
Xbox Live Primetime was unveiled back at E3, and aims to provide a meeting ground between gaming and TV.
Microsoft, initially, will use quiz games to achieve this; Endemol's 1 vs 100 show will be adapted into a massively-multiplayer online event for the Xbox Live community.