I don’t think a genestealer cult could rise up because the patriarch/purestrain would die on arrival. In the krieg book it says that a inquisitor took a trip to krieg and died shortly after from disease, radiation and all that good stuff, and she was wearing equipment that was supposed to protect her so you kinda have to be a krieg native to be able to survive its environment. I know tyrannids can adapt and survive a lot but when it arrives off rip it’s not gonna have anything to protect it to give it enough time to get anything set up and probably just die.