Welcome to the forum.....
Dodge calls the tube a "coolant return tube". Auto parts stores will call it a "water pump inlet tube" or "engine water pump inlet tube". The Napa website lists the tube as a "heater bypass tube". No matter what you call it, it returns coolant to the water pump from the heater core. There is an o-ring on the tube which can go bad and cause a leak.
I had a difficult time when I replaced my water pump about 2 years ago; it was because of a poorly machined pump I got from Napa. I posted about that experience here, maybe that post will help you:
If you have to replace your water pump, use the OEM tube from the Dodge dealer. It will save you a lot of aggravation. The aftermarket tubes do not fit correctly, or at least in my case it didn't. It is a good idea to use the Permatex water pump/thermostat gasket sealant that is made specifically for water pumps. It is kind of a bronze color. Coat the inlet tube above the o-ring with the sealant and lube the o-ring itself with clean coolant. You can also coat the outside of the water pump where the tube goes in with the sealant. These few steps will help to keep the tube from leaking.
I have not ever heard of common problems with water pumps, inlet tubes or coolant leaks on Dakota's. I guess any water pump can have problems at any mileage. Most of the threads I have read about it indicated the OEM Mopar pumps last at least 125,000 miles. I think it also depends on how often you drain, flush and refill with new coolant too, that helps extend water pump life.