I think most, if not all, of the remote individual permit systems have been opened up. I did a tour of the nebulae to the "south" of Sol (Pleides, Orion cluster, Jellyfish, Monkey Head, Heart & Soul, Bubble, etc) in January and most of them had a few permit systems but the permits seems to have been cleared since then. There are still several restricted sectors (Regor, Bovomit, Hyponia and a couple of others I think). Each of those is bigger than the human bubble so easily could contain a whole civilisation each. But since they can't be visited it wouldn't be fair to say that there are things to be discovered there now, they are just future possibilities.