Here is a weird question. If you are playing a Real Stars game - what happens if you run out of system names i.e. every system in the list is generated? Will the game just generate new random systems or are you done exploring?
You're not going to run out of system names. The list is too long.
There are around 4,400 Real Stars, so it is
extremely improbable to ever explore all of them in a single game - even with the improved efficiency of C# a game with so many systems would be slowed down to the point of being unplayable unless you very carefully limited how many systems could be "active" at a time (and the means to do this would make the game very repetitive). You're more likely to hit MaxTech before you explore every system, I think.
If you did somehow accomplish this, I believe under most circumstances what would happen is that any remaining jump points would link back to existing systems instead of generating new ones. If you wanted to generate additional systems, you would have to switch to Random Stars in the game options and set the maximum number of systems to be in excess of 4,400 or so.