If you google around a bit, the reason for building in Newark is simply that they needed a HQ with attached research facility within commutable proximity of the NYC talent market, and Newark made economic sense. The city of Newark is looking for green tech to move to the city, in the hopes of economic growth and luring other startups to Newark. So they were given a favorable deal to move onto a recently cleared brownfield site. It looks like their proximity to NYC consumers is just an added bonus.
However, the company initially was focused on the manufacture of patented technology and was originally focused on developing these urban farms in order to sell the equipment. The only veggies that the work in this setup so far are leafy greens. So you're likely very right about what this tech is intended to grow...
Some articles I found:
http://www.nytimes.com/2015/04/08/realestate/commercial/in-n...
http://www.nj.com/essex/index.ssf/2015/03/30m_vertical_farm_...
http://www.bloomberg.com/news/articles/2014-10-30/aerofarms-...
http://www.npr.org/sections/thesalt/2015/08/05/429345848/gre...
http://blogs.wsj.com/venturecapital/2015/12/10/aerofarms-rai...