Jonny in Harry Potter 4?

As our more film-minded readers may know, Jarvis Cocker (whom you know from Pulp) is doing the music for the new Harry Potter film, The Goblet of Fire. Franz Ferdinand were supposed to be featured in the film as a band of witches called the “Wyrd Sisters”, but have bowed out.
The Mirror says that Jarvis and our very own Jonny have replaced them. This goes in the rumor file for now, but you never know.