"Withdraw/Fail grades ARE included in the overall GPA calculation."
They are included in the GPA calculation in that it will appear on your application.
However, withdraws are worth 0 credits, so regardless of whether or not they are included, 0 credit of 0 credit is well... 0
So all they'll be doing is adding your (cGPA x # of credits taken) + (0 credit from W), then divided by (4(max GPA) x # of credits taken) + (0 credit from W) = (cGPA x # of credits taken) / (4(max GPA) x # of credits taken).
In other words, it doesn't count. Fs to though, because Fs are 4 credits attempted, 0 credits earned. Ws are merely 0 credits earned out of 0 credits attempted.