One of the more noticeable things about the trailers for Birds of Prey (and the Fantabulous Emancipation of One Harley Quinn) is that they have a crazy, poppy action vibe to reflect Margot Robbie's depiction of the wacky Harley Quinn. Sure, it will be a dark film in some ways, but this new tone is clearly course correcting for the dreary and dour Suicide Squad. However, one has to wonder if her greatest crime will be mentioned in this new film: the murder of Robin.
In Batman v Superman: Dawn of Justice, the Batcave featured a Robin suit defaced with spray paint. It was later revealed this Robin died, obviously at the hands of Joker. When Amanda Waller introduced the criminals chosen for her own tea in David Ayer's Suicide Squad, Harley's file described her as an "accomplice to the murder of Robin," so we know she had a role to play in the crime, which is probably why Batman wants to bring her in just as much as he does his nemesis.
Batman v Superman director Zack Snyder later confirmed the Robin was Dick Grayson, but the films themselves haven't actually confirmed which Boy Wonder died. Because of DC's 1988 Batman storyline "A Death in the Family," many assumed the dead Robin referenced in the DC Extended Universe was Jason Todd. In that comics arc, Batman found Jason dead after Joker beat him with a crowbar and then destroyed the building he was in. Whether it was Dick or Jason in the so-called DC Extended Universe, Harley did help to murder Robin.
Harley does want to chart a new course and atone for her sins, which she repeatedly told Deadshot, and seeing as she's protecting a young Cassandra Cain from Black Mask, she's trying to work her way back to the light. But the past can't be undone and this is a big stain. If Cassandra does become her sidekick and protege, surely Harley will have to address how she snuffed out someone's apprentice, which could really enrich the tapestry, connectivity and overall continuity of the DC Extended Universe.
This was a formative event and a catalyst in shaping Harley into a criminal, so rather than ignoring Robin's death, it'd add nuance to her character and show she's walking the walk and not just talking the talk in terms of redemption as a vigilante to address the event. Ultimately, Harley embracing and making amends for this act can help absolve her of her sins.
Conversely, Birds of Prey might move in a different direction and evade this dark arc, retconning it out of sight and out of mind. The DCEU wants a lighter vibe, and even if this film is violent and out of control, the creative team may decide to jettison this memory because Warner Bros. wants to move away from Snyder and Ayer. Their movies weren't as financially successful as hoped, and critics derided their films. So by forgetting Harley killed a Robin, Birds of Prey will definitely be re-framing her as someone a tad more virtuous than what the old days offered. The DCEU wants inspirational -- even if they're kooky -- crime-fighters, and so the studio may strike this crime from Harley's record to make her better for the future.
Directed by Cathy Yan from a script by Christina Hodson, Birds of Prey (And the Fantabulous Emancipation of One Harley Quinn) stars Margot Robbie, Jurnee Smollett-Bell, Mary Elizabeth Winstead, Rosie Perez, Ewan McGregor, Ella Jay Basco, Steven Williams, Derek Wilson, Dana Lee, Francois Chau, Charlene Amoia, Chris Messina and Matthew Willig. The film is scheduled for release on Feb. 7.