Board Thread:DC Universe Discussion/@comment-5624498-20150731235542/@comment-1038387-20150802215529

Killing Joke happened in the New 52. According to one expositionary flashback way back in Batgirl #1, and I don't think it's been brought up since.

Because you can retcon every character to fit a new timeline, but EVERY BATMAN STORY EVER has to have happened in five years because otherwise the fanboys get upset. It adds nothing to New 52 Batman, and even less to New 52 Batgirl. It's not needed to make a Batgirl, a stronger Batgirl, or, as Beware the Batman showed us, an Oracle.