News12 NJ is available on most, if not all Comcast systems in the northern part of the state (Ocean, Monmouth and north), which is why I think it's odd they do not want to add it to southern NJ systems; Burlington County on south.
I think News12 NJ is carried on Mercer County systems of Comcast, but that's always a fuzzy area: NY vs. Philadelphia.
I think News12 NJ is really trying to position themselves very uniquely and this is the first step. The northern part of NJ sees NY news, while the southern part of NJ sees Philadelphia news, but neither really sees what is happening in NJ as a bigger picture.
Yes, I'm really not sure how News12 can say exclusively on Optimum, just as NY1 says exclusively on Spectrum; neither of which is true anymore.