I think they will. I don't know what the legal position is, but I would think the germans would be liable for hefty damages if they suddenly cancelled them, and the German Cycling federation could well find themselves blacklisted.
I think the Germans are being holier-than-thou shoots over this doping issue. Why not pick on the sports where everyone knows doping is rife but nothing is done to stop it, rather than the one sport which is not afraid to confront the issue.