Its been convention that the nomad war is still a highly debated conspiracy theory that everyone in authority will maintain never happened.
Its not good for the votes. As for nomad "disclosure" I Don't think it would go past segments of the population that have access to spaceflight. LN and LSF as i recall locked down public interlopers around nomads and shooed them away back in the day. I dont know if thats still PAR or not.
I don't think workers or "ground dwelling" sectors of the population.. poor or indentured would have anything but stories and shaky cam footage from the neural net to go on.
Nomads, and the Nomad War are public knowledge. What exactly happened may not be known though. Most will just think it was some war on space squid things. I'm quite sure Rheinland spun the whole infection thing as minor corruption, though don't quote me on that.
Though, if anything most people won't really care. Remember there's more to the universe than space. People on the dark side of pittsburg worry more about keeping their job at the pizza joint than the major alien threat that is basically just rumored at that point.
I'd think, that societies have varying degrees of awareness about the Nomads. Cretans and Maltese, various zoners and such - are acutely aware of the nomads' existence. Mainly because nomads are... a fairly constant part of their environment. That is not the case for house populations.