'Ground Zero' will always be more important commercially than 'monumentally', only wishfull thinkers would think otherwise.
Commercial pressures will control the design/outcome, not grieving relatives, indignant Communities or plotting miscreants.
The land value per square foot will determine the resulting commercial project size and height....and at the other end of the scale perhaps 'normal' aircraft flight-path clearance limitations.
Public pressure will necessitate some 'form' of commemorative tribute/memorial, but commercial constraints will make certain it's not at the expense of the project's overall viability.
Welcome to the real world of big building...