To say that the DCEU timeline is currently a mess would be a pretty huge understatement. With the shuffling of directors mid-filming, Warner Bros.' constantly changing approach to building a cinematic universe, and multiple actors playing the same role, audiences can be forgiven for thinking the studio no longer cares about the interconnectivity between different films in the franchise. But in an interview with Empire, it was confirmed that Wonder Woman 1984 is keeping to the canon established by Batman V Superman.
"According to #Empire, #BatmanvSuperman is still canon in #WW84, and #Diana works at the #SmithsonianMuseum to keep track of any dangerous or mystical items, and lives in the #Watergate complex, where she has a view in any direction of Washington and can monitor the US government."
So the Princess Diana aka Wonder Woman we will get to see next will be the same character who showed up in Zack's Snyder's DCEU trilogy. What this means is that audiences will be already aware of Diana's backstory, and also what will happen to her in the future while watching her latest movie which takes place in 1984, decades before the events of Justice League, which is canonically her final appearance so far in the DCEU.
In a strange bit of parallel thinking, the MCU is taking the exact same approach to their most popular female superhero, Natasha Romanoff aka Black Widow. Nat's story ended with her sacrifice in Avengers: Endgame, and now her upcoming first standalone feature will jump back in time to tell the tale of an adventure that took place between the events of Captain America: Civil War and Avengers: Endgame.
The DCEU is giving mixed signals to fans in terms of movie canon. While films like Wonder Woman 1984, Shazam and Aquaman all seem to take place in the same universe, the one kickstarted by Man of Steel, other films like Joker, Matt Reeves' Batman movie and perhaps even Suicide Squad 2 appear to exist in their own universes, with no relation to the other films.
The upcoming solo Flash movie was supposed to set the record straight, with a timeline reset following the events of Batman V Superman and Justice League, which was rumored to reboot the entire franchise into a more coherent interconnected universe. But the film has been delayed for years now, and with Ezra Miller's recent violence towards a fan, Warner Bros. is reported to be considering dropping him entirely from the movie and getting a new cast together.
Of course, the nitty-gritty of what is canon and what is not won't bother the average moviegoer. All they care about is how much fun they're having while watching the movie. And that is where Wonder Woman 1984 appears to be winning out, with its trailer promising a rollicking, retro 80's adventure that is as heartfelt as its predecessor. Whatever may happen to the larger cinematic universe, the Wonder Woman franchise appears to be on solid ground.