Dishwasher Door Latch "kit"

I just ordered this ‘kit’, P/N AP3774456 and I did not get a clear answer as to the reason the "Door Gasket" is included. I have no (gasket) leakage and rather not go through the installation of the gasket if it is not needed; can anyone tell me why the gasket is part of this "switch" P/N?
Secondary to this is the gentlemen on the phone could not offer any input to the (gasket question or) statement; "the handle in the picture is different from the one I have, which is rounded"; instead of square, is this an aftermarket item or will I have a problem once recieved—I don’t think I will—just curious, thanks, pt