There are some interesting sentences on Kraftwerk in an interview with Dave Gahan (Depeche Mode) in todays Rheinische Post: (German language)

Translation: Q: "Did you know that Kraftwerk were once invited by David Bowie to support him on his US tour?" A: "Yes, but they didn't want to. Kraftwerk were no support band, they said. Nowadays they see it different."

Q: “Why?” A: “Well, there was a wish to tour with us.”

Q: “So you’re playing your forthcoming concerts with Kraftwerk?” A: “No, it wasn’t realised. Kraftwerk isn’t Kraftwerk anymore since Florian Schneider left”.