Hmm good point. Gives me a lot to think about.
We know from Alien that WY knew there was life on LV-426, so waiting ~50 years and choosing to colonize is certainly a weird approach.
But i'm under the impression that WY sent Newt's dad to explore the derelict once they found Ripley, making me think they knew about the derelict and were just waiting for the right time to breed aliens. I'm trying to recall events from Newt's tale to support my ideas. I'll have to revisit that comic.
I just have a hard time believing WY forgot about the Nostromo incident and decided to colonize randomly.