It's considered a strange fluke of luck that Ripley's shuttle was actually discovered, and it might have gone flying through the universe forever, with Ripley still asleep. However, it is *because* the shuttle is discovered that every character in the movie (and possibly the next two) that dies meets their fate. After all, it's not explicitly spoken but strongly implied that Burke is responsible for the colonists exploring the alien wreck because he wanted them to be impregnated so that he could somehow... make a profit from the R&D? Burke also knows of the alien wreckage only because Ripley told him the story. So, the colonists had lived on the planet for 20 or so years without a problem until Ripley's shuttle is discovered and she told the suits about the alien presence on the planet. It might have been better for all involved for her to have never been rescued...
Although I doubt Weyland-Yutani failed to notice that the team they sent to investigate a crashed Alien ship vanished without a trace...
It's quite possible that the W-Y execs who sent the Nostromo out in the first place buried the records after an expensive ship and its crew failed to report back. Meaning the company as a whole did in fact forget about the whole thing. The Fridge Horror there is that the company doesn't even remember what it did to Ripley and the Nostromo.
It's also quite likely that Burke didn't believe Ripley's story (or thought it was exaggerated), and that he sent the colonists to check that particular grid coordinate just to verify that there was nothing there - not as part of a nefarious plot to have the colonists impregnated.
The point is that Burke wouldn't have sent the team to investigate the crashed Alien ship if Ripley hadn't been found.
Whether Ripley was found or not the Aliens would still be there and the company was still terraforming the planet. The longer the ship went undiscovered the larger the civillian population would be and the larger the casualties would be when it was finally found. The really horrifying thing is that the movie is one of the better scenarios for how things could have gone down.
The heartwarming exchange of first names between Ripley and Hicks - it was the last time they ever spoke to each other. If you take the third film as canon however.
The addition of the Ripley's daughter subplot adds in a small bit of Fridge Brilliance. Ripley is the only one who's able to get anything out of Newt when she's first found. Of course a mother would be better than the marines at getting information out of an uncooperative child.
Newt's knowledge of the air vents and where they lead to make a lot more sense with the additional scene with her family. She says "all the kids play there" which implies it's a regular thing. She's also likely had a lot of extra practice travelling through them since the aliens started attacking.