My thoughts exactly. A lot of people won't want to consider this movie official, but it would explain why the company was in such a big rush to collect this alien species which, we originally presumed, they knew nothing about. Heck, the space jockey could have been transporting miniature space hamsters for all WY knew, so why would they want those in the bioweapons division?
They definitely knew beforehand what the aliens were like. Heck, even in Aliens, Burke was in a big rush to get the aliens back into the bioweapons division without really knowing that much about their capabilities, but if they had a record of the aliens life-cycle and lethal characteristics already, they'd know full well what they were capable of. So all-in-all, I would like to consider AvP part of the storyline. When I was watching the movie earlier, that line from Ripley in the beginning about if just one of those things reaches earth we're all screwed speech is chilling. Aliens have already been a major part of your own world's history and you don't even know it! I just love the idea, but of course I know others don't.