Sadly, there is a reason. P&B signed up to do 3 GP's. There is a monetary penalty if they don't do all three. The ISU did not allow any mercy for those who are ill. P&B chose to do 3 instead of 2 GP's because they felt they needed the appearance fees involved; so it is no surprise that they are trying to do all 3 rather than pay a penalty fine. Thank goodness, Fabian will have a chance to heal before TEB.
I don't think that allowing 3 GP's was a good idea at all, particularly when they are limiting each event to only 8 teams. It cuts the number of teams that can participate in the GP.
Weaver/Poje were also scheduled initially for 3 events, however they cancelled one. Was there a time constraint to make a change to your initial options?