6. More Standalones Will Follow
Through its first phase, the DCEU has very much attempted to play catch-up with the Marvel Cinematic Universe, which has negatively affected both its box-office and its critical reception. It's notable, though, that the movies that play the most into team-up events and the idea of a shared universe are the ones to fall flattest: Batman v Superman, Suicide Squad, and Justice League.
Wonder Woman had a strong box-office and great reviews, and now Aquaman's landed with great box-office and strong reviews. There were already signs that DC were pivoting more to these solo outings, but Aquaman should usher in even more of them.
Shazam! and Joker are on the way anyway, but this should give Warner Bros much greater confidence in tackling further standalone movies that break away from the shared universe aspect and work in isolation. Obviously, that includes The Batman and Wonder Woman 1984, but also some more risky and out-there properties that they might not have been willing to take a chance on had Aquaman bombed. Booster Gold, Blue Beetle, Nightwing, Batgirl, and even Green Lantern Corps all just saw their chances of actually happening - and working - increase exponentially.