Well, honestly its not that bad, its not destroying cannon because no one ever said its never happened and second it could have something to do with it being a Predalien. we've never seen one before so it is posible Aliens adapt, if it is a "Ultimate surviver" then it can adapt and you get anger for it adapting? Not the best idea but i mean honestly do you think when people saw Aliens they said, "What the Heck we never shall that thing before that shouldn't happen because the origanal didn''t have it" if you want a sequal to Alien that doesn't have anything new in it you will have aboreing movie and might as well hand them the script from "Alien" and have them make that. If anyything this makes Aliens Scarier and more dangerours