Point is, Doctor Who is a prime example of a show basically milking every story possible dry out of any existing story or concept. Its not impossible to find stories to tell with a new Doctor, so I don't trust that quote in any case.
Especially since it's just the latest mutation of the Moffat qote attributed to this team by Starburst, about having exhausted all the ideas about Christmas stories thathe could think of. Similarly the "five or six episodes" thing derives from the story that that was the condition Tilda Swindon would have put on accepting the role (which, some say, she was offered)
I've said before, and will again, it's fascinating to see how these rumours evolve and shift, bent to suit the propagandaof the week's haters.