We've never seen how long-range space travel functions in this continuity. It might well be very 'Star Trek'-like, for all we know.
But as a concept that just doesn't fit the more realistic world presented by the films. The sci-fi in the Alien movies is almost incidental. Sure they take place in space in the future, but the tech on display is very grounded. If we suddenly start having Star Trek parallel universes and such, it just wouldn't gel.
That's my view, though. It shouldn't
fit well, but the means by which it could come about is really unexplored territory. We don't know how ships are meant to traverse these enormous distances so quickly. If it does
involve some kind of warping/hyperspace effect, then if it's really just down to execution. It could be very 'Warhammer
'-like, with Lovecraftian spookiness hidden in 'the warp', just waiting to be found... I believe O'Bannon felt that way about LV-426, in general. He felt it was meant to have been a fragment from the world of some ancient cosmic gods. I could totally see zones of space with missing ships in it being treated like the Bermuda Triangle. 'Babylon 5
' did something similar and it worked fairly well.
There are all sorts of ways to bring various elements of that into it (to greater or lesser degrees), but the bottom line is that some kind of dimensional rifting/breaching could
fit the continuity better than we're all thinking.
I mean, just look at 'Event Horizon
'. I'm not expecting it to be on that level, but that's a film which very much feels like it could
fit into the 'Alien
' series. The kinds of characters, the way they react, talk and even dress... It's clearly influenced very strongly by our series. Yet, that handles dimensional breaching in a way which feels plausible when you're watching it.
It's not the kind of plot device I'd favour, personally, but I'm not going to assume it couldn't be done right.
And if that means we get Sean Pertwee as a gruff Colonial Marine, I'm all for it!