“Space opera is a subgenre of science fiction that emphasizes space warfare, melodramatic adventure, interplanetary battles, chivalric romance, and risk-taking.”

So yeah, space opera does mean science fiction. And while I won’t claim to know the story better than the author, I do know genres. That quote from Lucas really put all his references to fantasy in perspective. He is using that word to distinguish from 2001 type science fiction which is near future, real world, and possible (aka Hard Science Fiction sub genre). He is making it clear that his tale has no relationship to the real world. Well, all he needed was space opera, but that doesn’t work for the common person who has no idea what that is. However, for those of us familiar with all the genres and sub-genres of fiction, space opera automatically places it in a fantastical world where technology isn’t clearly defined and my not actually be possible even if they make it sound plausible. Hyperspace, while sounding logical and setup with some clearly defined rules, is about a real and scientifically possible as Yoda levitating an X-Wing. That is space opera (yes, even Yoda levitating an X-Wing). It is a direct successor to the old planetary romance sub-genre (like John Carter of Mars). It has been a staple of science fiction for over a century. So saying it isn’t science fiction is quite inaccurate. And that quote from Lucas shows he knew exactly what genre he was doing and he was doing a PR spin to make sure it was clear to the general public. Space Opera has never let accurate physics get in the way of a good story.