Supposedly, Niall Paterson's "The Early Rundown" is to come from Studio 21, so is the weekend "@Breakfast". Weekend daytimes are also apparently coming from Studio 21. Kay is to get a new set (or at the very least a new desk) at Millbank in the new year.
That means that Studio 6 will only be used for World News from 00:00-06:00 or when there is maintenance in Studio 21, and the VR area only used for pre-recorded segments.
GALLERY 21 is where all the main studio output comes from - whether Studio 6, the glass box, or Millbank.
This should not be confused with STUDIO 21, which has nothing to do with Sky News.
Niall's show will come from Studio 6, as will Stephen and Gillian's show (they'll take turns hosting the early slot on Fridays) and weekend output pre-8pm.