First, in general, stay away from Wikipedia if you want good info about the mob.

Second, you can read the actual report that's online. If you Google "Changing face of organized crime in New Jersey" you'll see the full PDF version. A shorter, easier to look at form of the report can be read at the link below.
http://mafianj.com/sci2004/index.shtml

Third, here's the excerpt in question:

Despite the assaults by law enforcement and the apparent slowdown in membership recruitment, law enforcement authorities estimate the group still consists of from 110 to 140 members, with approximately 50 members active in New Jersey. The organization has at least 1,100 associates engaged in criminal activity primarily in New York, where the group’s hierarchy is located. New Jersey operations span Essex, Union,  Monmouth and Morris counties. Law enforcement authorities believe that most of the New Jersey members and associates of the Lucchese family reside and conduct much of their business in Morris County.

So, I suppose one can be excused for believing the family's New Jersey crew has 50 members, even though the report isn't referring to just that one crew. The family, of course, has other NY-based crews that have operations in New Jersey. In fact, the report talks about "commuter mobsters" who live elsewhere but travel to New Jersey for work.

However, I do question the figure rising to 50 even with them. The reason being, some other figures in that particular report seem to be inflated a little. The family would be a lot closer to 110 than 140 members. 100 members or so was the last estimate I saw. And half of them are active in New Jersey? That seems excessive. Especially when, elsewhere in the report, you have the Genovese family, which is said to have several crews based in the state, plus others that have operations there, only having 40 members active there. The 1,100 associates for the Luccheses also seems high compared to other estimates.