I hope DARPA is smart enough to put this out for bid again. There are more players than in 2013 that could fill the role better than Boeing...
It was a technology demonstrator, designing something that was never built before. DARPA was looking at developing technology and perhaps the technology was found to be unworkable. This is what usually kills most technology demonstrators.
It is good we set the bar high so we push technology further and/or find new technologies or maybe finding the technology envisioned by DARPA was found to be unworkable.