I think the Zucker brothers were in the opening scene directing the 747 that crashed into the terminal. Kind of like Hitchcock cameos.
What really made the movie a classic was the insistence by the Zucker bros and Abrahams the dialogue be delivered straight in total seriousness.
They were getting a LOT of pressure from the studio to do it as a “normal” comedy but they stuck to their guns and the rest is history.