I get it; not very sci-fi.

Well, they want to preserve a role for the editor; because the editor is not just checking the grammar but also the content, and weighing in with their relative objectivity on the current state of the story, what should be improved, what was good and what didn't work, etc. and if we have AI glazing us continuously we will just produce slop; it may look like good fiction but it will not read like it, and people can tell the difference!