This might not technically qualify as a theory, but here goes:
Whenever a character dies, it is always another character who narrates their late companion's death. Since presumably Michael and a few others are recounting these events after the end of We're Alive, this would seem correct. *SPOILERS* Narrations by characters who have died since their segment of narration were passed on through journals or in Lizzie's case an audio recording device. This is why Kalani's journals were so important. So if a character is narrating, one might be able to safely assume that they are not in immediate danger. I say immediate because Datu was bitten under his own narration. As saddened as I was by Saul's supposed death from the episode released yesterday, I was prepared for it. Michael's narration suggested that he would be safe, as well as the fact that the series seems to revolve around him (Although this doesn't cement his safeness. We're Alive's cast is so awesome across the board that even without Michael the show would still keep on chugging). Not every character is keeping a journal now. One's to consider are Victor, Pegs, Tanya, Puck, and Kelly. If any of them are narrating and don't state anything about backing up a copy of their narration in a journal or Tanya's laptop, then there's a chance that they are safe. On the other hand, since these characters (with the exception of Tanya) don't narrate much, that could suggest that they are in danger.
Thought?