I hope this is the right place to post this. I've never posted here before and I'd just like to get my opinions out there about the game and I've never seen anyone else post this theory, so feel free to tell me I'm an idiot or whatever afterwards.
But WB Montreal is making Origins a sequel to take you back to Year 2 of Batman's career to show you how he used to be as a character when he was younger and less experienced, how he got to where he is as a character in Asylum, as well as all of the other characters and even Gotham itself. And while I don't doubt that, I can't help but feel like it's also just to have an excuse to bring The Joker back. Black Mask may be the main baddy of this game, but so was Strange in City, and if you played it, you'll probably remember Joker sort of stealing the show. I just feel like the same will happen here.
Now this is also a time when most of the police force is corrupted, Commissioner Gordon isn't even the commissioner yet, and Barbara Gordon is still a teenager I believe, and she's just starting to look up to Batman's way of fighting crime. I remember Eric Holmes vaguely kind of confirming Batgirl was going to be in this game, and Barbara herself has already been shown in footage. You'll also remember she's already Oracle in Asylum and City.
This is also the first time Batman meets The Joker. He's obviously not one of the 8 assassins, but I also don't believe he's just part of the side quests like Anarky or Mad Hatter are. There's no way the collector's edition would come with a statue of him, there's no way he'd be getting this much coverage in trailers, and there's no way Troy Baker would be getting this much press for voicing him if that were the case. He's already got more of the spotlight for voicing The Joker, than Roger Craig Smith does for voicing Batman, the main character. If you recall, Troy also recently read The Joker's monologue from The Killing Joke at ComiCon, and I don't believe it was just a coincidence.
Here's my theory. I think that something big needs to happen with The Joker in this game to sort of cement his and Batman's twisted relationship, and to bring them to where they are in Asylum. Now I don't remember what year of Batman's career The Killing Joke happened, so I could be entirely wrong, but the Arkhamverse doesn't necessarily follow the comic timeline, it's its own universe with its own canon. So I think that they could reenact their own version of The Killing Joke story where Joker paralyzes Barbara. Unless WB Montreal decides to keep making sequels to this prequel storyline, I think it's possible that's what's going to happen in Arkham Origins.
Please, discuss your opinions. I'd love to hear your thoughts on this.
TL;DR - I think The Killing Joke story is going to happen in Arkham Origins because reasons.