If I understand it right, you're not sure why people of Sirius wasn't informed about Nomads even when Atticus Rockford saw them and came to Liberty? It's all simple. Probably, he was simply "muted" by government or closed into asylum as a madman. Simple.
Yet there's no indication that any of the governments knew what the hell was going. You can't just patch up a major plot hole by saying what might have or probably happened, you need to support it with lore or canon events in-game. Of which, to my knowledge, there are none. Not even any that have been loosely fabricated in Discovery lore. Pretty much the only thing that supports the extended intro being canon is that Igiss said it was. What in-game actually supports this being the case?
![[Image: SLRU.png]](http://i668.photobucket.com/albums/vv46/Nighthawkashes/SLRU.png)