Yeah I might have reversed them in my head they came out within a month of each other.
But I do vaguely remember people debating which was technically first. And marvel specifically calling out Hulk as technically first. Maybe because of which order they were planned on, or because Hulks ties were more explicit.
By the time they started talking about Phases and publishing explicit lists of which and when future movies would be coming out Hulk seemed to have been removed. Rather than regarded as the 2nd film. So that film is tied to the MCU but the MCU isn’t too tied to that movie.