As for why it's such an obvious pick, well, Helldivers 2 and 40k occupy a lot of the same 'satire of intergalactic fascism' ...
It could just be the divers getting the heebie-jeebies, but it looks like Arrowhead could be teasing the squids doing a thing.
"The Helldivers are ordered to strike deep into Automaton territory with the objective of liberating Chort Bay and destroy ...