This is something I have discussed with the powers that be.
Unfortunately this isn't Star Wars where you could pick any element and make a story around it that will find an audience - Jedi, Sith, rebels, empire, first order, seperatists, bounty hunters, or myriad other things.
With Alien, it needs to be tied to the creatures in some way, or failing that the USCM which is the next most popular aspect.
We had backstorys to the Covenant crew and some marines and they've generally been regarded as the weakest stories of recent times. Years ago DH press did a few books that pushed the Aliens into the background and they're not exactly fan faves either.