With Justice League Snyder Cut. With the latest DCEU movie being set between Wonder Woman and Diana's later appearances in Batman V Superman and Justice League, it has to do a lot to keep it canonical.
While there has definitely been a strong attempt made to make Wonder Woman 1984 fit within DCEU continuity, it also falls down several times too, particularly in regards to the Justice League: Director's Cut, which has a lot more plot to contradict.
s: Staying Out Of The Public Eye
One of the big plot points involving Wonder Woman in Batman V Superman and Justice League is that while Diana Prince is fairly well-known, her heroic alter-ego is virtually unheard of. Bruce Wayne, the great detective, had never encountered her, and the only photographic evidence of Wonder Woman is a hundred-year-old picture. While Diana has to leap into action in Wonder Woman 1984, she always makes sure to destroy security cameras so there is no physical evidence of her hero work.
Contradicts: Speaking To The World
While Diana goes through a great hassle to make sure she isn't caught on camera in her Themysciran armor, she isn't above allowing regular people to see and hear her. While for the most part audiences can write off these appearances as no one believes these people, this does not explain what happens in the final act of Wonder Woman 1984, as Diana speaks to the entire world. Supposedly no one knows her in Justice League, but addressing every human being on Earth must have caught someone's interest.
s: Diana Remains An Antiquities Expert
In all the DCEU movies featuring Wonder Woman beyond where she was storming through No Man's Land, Diana is portrayed as an expert in the ancient art world. In the present-day sections of both Wonder Woman and Justice League, she works for the Louvre in Paris, and in Wonder Woman 1984 she's an important part of the Smithsonian, enough to have access to classic planes and a runway.
While this doesn't play much of a plot role in Zack Snyder's DC movies, in the Justice League Snyder Cut Diana investigates the ancient Shrine of the Amazons, where she finds out about the Mother Boxes and Darkseid.
Contradicts: Where Is The Mother Box?
The big push for the DCEU was to introduce not only the Justice League but also set up the Mother Boxes and the Apokoliptian invasion of Earth. This is even more important in the Snyder Cut, which brings in Darkseid, Desaad, and more revelations about the Boxes. Wonder Woman has a deleted epilogue where Etta Candy and the Wonder Men actually go after one, but Wonder Woman 1984 completely ignores this scene and the Mother Boxes in general, with no setup towards Darkseid.
s: The Old Gods Died
One of the major differences between the DCEU and the comics, particularly in regards to Wonder Woman, is the status of the actual gods, such as Zeus and Ares. Hippolyta told her daughter how Ares killed all the other gods, and Steppenwolf confirms to Diana in Justice League that the Old Gods are dead. Wonder Woman 1984 confirms this. While the Dreamstone was created by Dechalafrea Ero, the God of Lies, the old god himself remains absent for the entire movie. This is important to the Snyder Cut, which pushes further into the New Gods mythology with the inclusion of Darkseid.
Contradicts: Asteria Could Have Helped
The golden-winged armor seen in all the posters and trailers for Wonder Woman 1984 belongs to Asteria, the greatest warrior the Amazons have ever known, who was vital in covering their escape to Themyscira. As the movie reveals, Asteria is super-strong and nearly immortal, as she's been on Earth for thousands of years and still helps people. And yet, she doesn't help in the fight against Steppenwolf. If Hippolyta fought in the original battle with Uxas/Darkseid in the Snyder Cut, Asteria was surely there too, and she would also know that a flaming arrow in the Shrine of the Amazons means an invasion.
s: Themyscira Is Still Lost
The paradise island of the Amazons, Themyscira, is a vital part of Wonder Woman lore, but it has one major complication for a filmmaker: Diana isn't allowed back there. After leaving in 1918 to help Steve Trevor, Diana was forbidden to return to her home.
In Justice League, the only way Hippolyta has of ing the outside world is to light the ancient fires, as she cannot simply speak with Diana. Keeping in continuity, in Wonder Woman 1984 Themyscira appears only in a flashback and doesn't directly feature in the plot.
Contradicts: The Golden Armor
In the final battle of Wonder Woman 1984, in order to counter the newfound strength of Barbara Minerva, Diana dons the golden armor of Asteria to protect her. Cheetah puts up a powerful fight, forcing Diana to abandon the armor's wings, but ultimately Diana is successful in her fight. Unfortunately, this creates a problem with Justice League, as the armor of Asteria should still be in Diana's possession and would be very useful in the battle against Steppenwolf and Darkseid. The armor is nowhere to be seen.
s: The Age Of Heroes Will Come Again
Wonder Woman 1984 exists in a weird time in the DCEU where there are no superheroes, but the world is on the cusp of being introduced to them. There have been gods, aliens, wizards, and Diana herself walking the Earth, not to mention eventually Batman just a few years after the movie, but it's not until humanity is introduced to Superman that this world becomes public. The Justice League Snyder Cut will double-down on making clear Diana's assertions that the "age of heroes" has come again, but in 1984 the world is still not ready for costumed crimefighters.
Contradicts: Batman And The Dreamstone
1984 may exist prior to Batman, but Bruce Wayne is absolutely alive at the time of the second Wonder Woman movie. Unfortunately, this creates a logic problem for Justice League. According to Batman V Superman, Bruce's parents died in 1981, just prior to the release of the movie Excalibur. Three years later, if someone like Max Lord came along and gave young Bruce the chance to wish his parents back, he for sure would do so. He would then be traumatized further by having to give them up again. At the very least, he would Diana, the woman who persuaded him to renounce his wish.
