On March 13, 2014 the Triple Five Group announced a settlement was reached with the New York Giants and New York Jets allowing the long-delayed project to move forward. Construction has been ongoing since November 2013 and was expected to pick up in early 2014. Although no timetable for completion was announced, the developer originally said it would take about 24 months to complete the project once construction began.[19] That April, Triple Five released a revised design for the mall’s exterior and confirmed a tentative opening date in late 2016.[20]
https://en.wikipedia.org/wiki/Meadowlands_Xanadu
I believe you are referring to the construction for its new role; the original construction was completed on the mall, and now they are looking to change it to another purpose.