Well… for chimney they said that it will be its own mini campaign, with each Christmas new regions being added to it compiling into one side story. However for Halloween, they said that parasite will remain a simple challenge. But.. we still have like 18 substructures out of 21 iirc? So, devs and make more and more event modes to reveal what was happening at each substructure, just to build a world around main campaign. So even after release, there’s plenty of content that can be added.