Sure, I get that part. However, since most people know what the xeno looks like, in order to make the film scary (for me, anyway), I think they should show us something different.
Not having seen the film yet, I can't say that the xeno may look different in some way or do something we haven't seen it do in other films. However, if the trailer is an indication of the film and the plot, this will play like some sort of slasher film. We've all seen slasher movies...and honestly, I don't find Jason frightening anymore. Entertaining? Sure, at times. Scary? Not to me. And I'd *like* to be scared!
I suppose the only way they can do that is to come up with a newer version that isn't solvable versus their technology. However, since it's a prequel... they are limited to what they can do with the creature.
For me, real life is always scarier than science fiction... Watching Contagion or even a Rob Zombie movie would be more creepy than Alien, even though I still enjoy those films.