I don't take any issue with people flagging a post, so long as an actual person makes the ultimate decision on whether to keep it up.

This is in contrast to how I feel about a statistical model flagging people to be murdered. That's not even remotely OK, even if the decision to actually carry out the murder ultimately goes through a person. Using a statistical model to choose targets is incredibly naive, and practically guarantees that perverse incentives will drive decision-making.