I heard(probably on these forums years ago) that one of the ideas of the expansion pack that became Primal Hunt was to make it a sequel instead of a prequel, there would be a conflict during the Verloc's evacuation from LV-1201, the game did end with the predator ship going after it... it seems it would involve some Dunya vs Harrison stuff, but since we know she ended up making to Gateway Station and was continuing Rykov's plan, Dunya wouldn't have been killed.
I imagine the predator ship would attack the Verloc, somehow aliens would have gotten on it through some evacuation ship, Dunya and the rest of Rykov men would have used it to escape.
I think the reason there wasn't a sequel to monolith's one was because of rights dispute.
You mean with Fox? Or by Monolith Productions being acquired by Warner Bros?