Not exactly. Its just saying humans eating humans is wrong, but other creatures eating humans is not a moral issue. Rules about specific animals are additional rules.
Yeah if the alien is a dinosaur or some other animal on another planet, yeah that will probably eat you, but I do not think aliens eat humans.
Oh, wait, are you concerned by the reference to aliens because it disrespects aliens? Is this a belief that more intelligent creatures would have a moral obligation to eachother?