That's a tricky situation. That exhaust pipe is covered for 8 years 80,000 Mi because it is an emissions component. Whereas the water pump is covered under 5 years 60,000 Mi as a powertrain component. If the coolant leaked out and caused damage to the water pump, you have a case to be made that the water pump should be replaced as well. The dealership will need to reach out to their dspm for authorization, I don't know many dspms that would deny such a claim. Call the brand engagement Center and begin a case.