Aquaman may have discovered the secret weapon to help turn the DC Extended Universe around: better marketing.
It cannot be denied that the franchise has been divisive; even if one likes the darker tone, their writing and editing so far have been question (Wonder Woman being the exception). Aquaman hopes to avert those problems, but unfortunately, does not exist in a vacuum; even if it does turn out to be great, it has to convince potential viewers of that fact.
Take Justice League. Most viewers agree that it is better than Batman v Superman: Dawn of Justice, of which it is basically a direct sequel; however, it made about $200 million less over its run, because by the time that it came out, the general perception was that DCEU movies were bad. Even Wonder Woman had a fairly modest opening weekend, but picked up steam when word of mouth confirmed that it averted the franchise’s major problems.
Right now, Aquaman is undergoing reshoots, just like Suicide Squad and Justice League did. However, director James Wan has done a good job at downplaying this; on his Twitter account, he euphemistically announced that they were doing “pickups,” and emphasized the fact that Randall Park (of Fresh Off the Boat and the upcoming Ant-Man and the Wasp) would be added to the film as a result. It is unclear how extensive these reshoots are, but he at least made them sound minor, which helps to avert the “DC movies don’t know what they’re doing” narrative.
Wan is good at public relations in general; his past projects (Saw, The Conjuring, Fast and Furious 7) have all been popular, and he does a good job promoting them, mostly on Twitter. He even went so far as to poke fun at the underwater bubble scene in Justice League about a week after the film came out, which helped build a fun rapport with fans. (A similar dynamic has occurred with David F. Sandberg, who is directing Shazam.)
In short, while we don’t know how Aquaman will come out, Wan and Warner Bros. are doing a good job so far controlling the narrative around the project, dispelling the fears that have negatively affected past DCEU projects.