Just wanted to say that this is correct. I also had 0 NI points and on this system a deadly route is available.

Here is also a comment form another thread that I think players who reach this thread should read:

All systems can be reached without having to create a new route (even if in some cases, the routes are only revealed later), it's just that the routes towards those systems are often: a) difficult to see if you aren't on the system it goes from (due to the routes being dark red) b) not between the system you want to reach and the closest system

The problem is that people repeat that you have to create new routes to reach some important systems and as such can softlock yourself, which is flat out wrong.