David Morrissey said on Radio 6 that they're trying to stage it at Manhattan Theatre Club in April 2017, with as many actors from the original London cast as they can get.
Sadly it isn't. It was going to be the MTC spring show at the Friedman but it has been replaced by Little Foxes. Basically the cast and director of Hangmen said either we all do it on Broadway or none of us do it on Broadway and that wasn't logistically or financially possible for MTC, which is odd because thats exactly what they did with that horrible Pitmen Painters. I was lucky enough to see Hangmen in the West End and the NT Live version is pretty good if it ever gets re-screened.