The buildings are only one part of the equation to complete. A significant effort is required to complete the landscaping and paving. This requires integration of electrical power systems, low voltage such as AV, irrigation, lighting, graphics, signage and way finding. This part is generally at the limit. Ticketing and entrance systems can also cause a blip and not to mention the occupancy permit.
But the management team are experienced and one can expect that these home stretch activities are carefully integrated in the project time frame.