By the time Justice League 2 talk could resurface, it isn’t crazy to think he’d have at least one or two more films to learn qualities of a good leader.
He might still retain some of the knuckleheaded-ness he displayed in Justice League, but ideally he’ll mature as king enough to power through some of that.
As of right now, the answer is no, but Aquaman’s financial success has all but guaranteed that Arthur will get more adventures to polish his leadership skills.