LV-426 Explained: Weyland knows about it but deters others from knowing

I just picked up the BluRay today! First thing was to look at the extras, The Peter Weyland Files. Going in you have a choice to play all or play one you want. However, if you look to the right of the playable videos there will be what looks like an email communication. This is a written recording of some type of dictated note BY Weyland, and in response to the specific Weyland File you are on. Looking at recording #1. Quiet Eye: Elizabeth Shaw, Weyland tells us that they picked up a transmission, FROM LV-426!!! "As fate would have it, Shaw and Halloway's interest in Zeta 2 Reticuli has proven to be mutually beneficial. While the good doctors rely on ancient carvings and primitive cave paintings, my science division's own long range scans have recently detected a faint, almost imperceptibel signal eminating from one of the lesser moons in that system. And contrary to the findings of Shaw and Halloway, which target LV-223 as our primary site of interest, our findings suggest the point of interest could actually be the moon LV-426. Per standard procedure, we will embed a David 8 unit with the crew. And he will be programmed with multiple contingency plans to address and exploit whatever assets we secure on 223. But only David will know about 426 and will ensure that the rest of the crew - including Meredith - learn nothing about the transmission we've recently discovered until the time is right. For if the Yutani's new ECIU software is to be trusted, there might be great risk awaiting us on the path to an even greater reward." So folks, there it is. Alien LV-426 was known, its the same system, and the transmission was intercepted 30+ years before Ripley landed there.