No, two of our lines are eligible for upgrade (old iPhones are paid off). Upgrading one line and adding a new line to get the $700 credit. Then we are cancelling the other upgrade eligible line since there is no payment plan attached to it. The net number of lines does not change, but technically we added a new line and are eligible for the credit. The only issue is that you lose the number associated with the line being cancelled.
[doublepost=1537640190][/doublepost]FYI, you apparently can't cancel lines in store in anymore. You have to call Customer Service. I am probably going to wait until the middle of next week, as I imagine Verizon customer service is slammed with iPhone/Apple Watch activations.