It's not quite DC and Marvel teaming up, but it is sort of like Superman and Batman becoming official partners after teaming up a bunch of times in the past—Blum has been a producer on Wan's movies, and the two clearly have a good relationship.

Source: https://boingboing.net/2023/01/01/jason-blum-wants-an-invisible-man-sequel.html

James Wan's initial working title for was "Necrus" – a name fans of the soaking superhero's comic adventures will be deeply familiar with.

Source: https://screenrant.com/aquaman-2-lost-kingdom-trailer-story-release-date-news/

Some fans return to James Wan's long-running franchise for the story.

Source: https://collider.com/scream-6-best-late-horror-movie-sequels/

's success is leading to the game making its own medium expansion with a movie adaptation produced by Blumhouse Productions and James Wan's Atomic Monster.

Source: https://screenrant.com/terrifier-art-the-clown-video-game-haunted-house-experience-creator-plans/

Wan's movie charts Aquaman's journey to becoming protector of the ocean, which is narrated as inextricable from the superhero learning to embrace his mixed-race status as a source of strength and power.

Source: https://www.salon.com/2023/01/02/aquaman-wakanda-forever-avatar-blue-humanities/

While not an outright confirmation of a future in the franchise, Wan's explanation of how Aquaman and the Lost Kingdom was changed to fit Gunn's DCU does indicate that Momoa's Aquaman will continue past the upcoming sequel.

Source: https://screenrant.com/aquaman-2-dcu-changes-james-wan-response/