The DCEU still can't stop referencing Jared Leto's Joker, with The Suicide Squad including a nod to his take on the Clown Prince of Crime via Harley Quinn. Leto was cast as the Joker in Suicide Squad all the way back in 2014. At the time, as part of the burgeoning DC Extended Universe, then it seemed likely it would lead to many more appearances, even despite a controversial first look. For myriad reasons, though, that never quite worked out: Joker's role in Suicide Squad was significantly altered (and reduced) by the studio, and the negative reception effectively meant the end of his time as the character.
The casting of Joaquin Phoenix for Joker was seemingly the final nail in the coffin for Leto's iteration, especially when it made over $1 billion at the box office. But with that existing in its own universe, then there's still room for the DCEU's Joker, in some ways, at least. Leto may not officially have much of a future as the Joker as it stands, but that hasn't stopped various DC movies from referencing or bringing the character back.
This first happened in Birds of Prey (And the Emancipation of One Harley Quinn), which built off Harley and Mr. J's relationship and breakup as Joker appeared in flashbacks, played by Johnny Goth. Then, Zack Snyder's Justice League added Leto's Joker into its Knightmare sequence, one of the parts of the movie added after its official release announcement. Now, The Suicide Squad's trailer features a nod towards the character, as Harley wears a jacket that says "live fast, die clown."
It's an interesting choice, especially given Leto's Joker isn't returning for The Suicide Squad, and in general the movie - and Harley - seems to be moving on. Of course, Mr. J was a huge part of Harley's life, and so isn't easily forgotten, which perhaps makes this a rather fitting nod to the character. It shows that Harley does still remember and even think of him, but in a way that cements how little she'd now care if he were to die. This pairs well with her new tattoo in The Suicide Squad, which now reads "property of no one" having previously been "property of Joker." It keeps with her character too, with her attire previously sporting other messages such as "Daddy's Little Monster," through which lens this seems like a real (and humorous) upgrade. The Suicide Squad's place in DCEU continuity is deliberately vague - it's not a true sequel, but isn't a full reboot either - and this is a subtle way of highlighting Harley's backstory, and not completely eradicating what came before with Joker.
Of course, the bigger question is whether this will lead to anything more for Leto. Although the character wasn't well-received at the time, his Joker has gained some sympathy because of how much it was revealed was cut from Ayer's Suicide Squad. Similarly, Joker's appearance in the Snyder Cut, while very different to his first outing, won plenty of praise from the movie's fans, and did setup more to come should the Snyderverse ever be restored (though that also remains unlikely as it stands). Still, it's a position whereby Leto's Joker is gone but definitely not forgotten in the DCEU, suggesting the door does remain open for a return somewhere down the line, even if The Suicide Squad means it feels like his and Harley Quinn's story really is over.
