Is Zack Snyder’s Justice League official DCEU canon? The fans would almost certainly answer that with a resounding yes, while Warner Bros. would counter with a firm no. Even the director himself said that Joss Whedon’s theatrical release was the one to accept as part of the franchise’s continuity, before backtracking after the release of his HBO Max exclusive and saying people can decide for themselves.
One thing that had never been canon up until the Snyder Cut was Mera’s British accent. For some reason, the filmmaker and Amber Heard decided that in order to reflect her regal background, the character should adopt a prim and proper dialect, although they never thought to consider that the actress might not be able to pull it off convincingly, which she most definitely did not.
However, that’s not the only major change to Aquaman’s love interest that was made in the four-hour superhero epic, and another slight alteration contradicts DCEU canon in a minor if still significant way. In the theatrical cut, Mera remarks to Arthur Curry that she knew his mother Queen Atlanna, who took her in while her royal parents fought in one of Atlantis’ many undersea wars.
In the Snyder Cut, though, the dialogue has been changed and Mera instead reveals that her parents died in the war. The only problem in saying that is technically Justice League occurs before Aquaman, and her father is very much alive and well there, played by Dolph Lundgren with a spectacular ginger wig and beard combination, no less.
Of course, DCEU canon is nothing short of a total shamble and has been for years, and Zack Snyder’s Justice League by all accounts exists in its own plane of existence, so these things can be easily overlooked and swiftly forgiven.