I'll admit it's been a good while since I've seen Aliens so I could be forgetting some stuff but the only thing they seemed to reenforce was that Weyland-Yutani is a horrible, profiteering corporation that neglects its people, sacrifices lives and is only in it for themselves. But we already had a good idea about that from Ash's actions toward saving the xenomorph and from Brett and Parker complaining about their shares in the company and whatnot. The weasely exec Burke in Aliens was such an utter caricature you could predict his behavior from moment one. We didn't get much more on where the aliens come from or what happened to the Pilot, which I guess we're getting to now with these prequels (don't get me started on Prometheus). I don't know. Maybe I'm forgetting something. I'll have to rewatch it and get back to you.
