I really would like to believe this was a mistake by an editor, but as someone who voluntarily edits in this publication also, I am super careful. I never ever chang the tone or what a writer is saying in a story, no matter how they express it. I always add a separator at end of story and underneath put the publication footer. It would be inconceivable to add content to a writer's story without their consent, let alone plagiarise another writer. This kind of thing makes me feel unsafe. If another editor can do that, I will keep a close eye on my stories. This is absolutely 100% wrong, big time. I would love to think it was an unfortunate mistake but it's very fishy.