I think Abraham is the least important character that can die and leave some viewers angry, but it will probably be worse than that. I don't think there has been a season finale (possibly not even a midseason finale) without someone getting killed. I have two guesses, but I will keep that to myself. I think it is less likely to be a zombie - half the point of the show is that the humans are capable of so much worse than zombies, and we just lost Chris and Deanna's son to the zombies.
Gabriel is probably going to do something really retarded to cause bad things to happen. Maybe he will let the zombies in.
The people in Alexandria have no idea what is outside their walls, which is why they run things the way they do. I am pretty sure the show suggested that hardly any of them had actually faced a zombie. All they have is their incompetent runners, who we know like to lie, and probably come back talking tough after peeing their pants and running from the zombies. The smart thing to do would be to let Deanna run the town and Rick's group run every last bit of the defense, which was what she seemed to be allowing until the disagreement over wife beater dude. She made a political decision to ignore it because the town has to have a doctor, and Carol can't ignore it because of personal experience, while Rick can't ignore it because of who is getting beaten. If Deanna confronted wife beater dude, he probably threatens to hold back his services. This is why certain college QBs never have to answer for their indiscretions.
The solution is to cancel his ass and take a convoy back south to pick up some new doctors from the hospital where Beth died.
Abraham's lady did look better in the Tomb Raider outfit, but who wouldn't? Besides dudes, obviously.
It would be a great fakeout if it was Darryl or Carol that died and not the mystery guest. Except for the part where Darryl or Carol would be dead. It might also be interesting if the whole story about the spinoff series was a lie and it really happened by half the cast leaving Alexandria and half staying, mixing things up.