Yes, and Pier G would certainly simplify the need for swing gates that alternate between USA and International flights by allowing all US flights to be located in the one pier. By opening up the arm of Pier F to the Hammerhead it would also make it appear much more roomier.
My biggest criticism of F has been that they have stuffed it full of retail and left little room for the actual passengers. There are bars now on the outer perimeter of the terminal, where there would normally be seats for passengers waiting for their flight. I don't fly very often however when I flew out of F in 2009 it seemed more spacious than when I next flew out of F in 2015, and the only thing I can see different is the retail.
There really should be enough lounge seating in the terminal near gates to hold all the passengers ready to board a flight, plus a buffer to allow for carry on baggage, and the natural human preference to not sit in close proximity to a stranger. So in the example of at 400 seat 777 we are talking about 400 plus seats in the terminal. Some seats can be shared between adjacent gates given that not every passenger will be waiting at the gate all the time and not every gate is in use at the same time. But I digress.