Why is the Outer Court not mentioned in Heb 9:1-2?
Because the book of Hebrews is following a line of presentation.
In chapter one, he introduces us to Jesus as the conduit of divine communication.
In chapter two, represents Jesus as the perfect representation of humanity. He is the bio-representation of God.
In chapter three, Jesus is the architect of the house of God.
In chapter four, he is the rest giver.
In chapter five, he is presented as the High Priest.
In chapter six, he is the surety of the oath and the promise.
In chapters seven and eight, his priesthood is represented as the superior priesthood.
In chapters nine and ten, he is setting up the tabernacle for the day of atonement and our attention is being drawn more to the High Priest as he prepares to enter the Holy of Holies. The sacrifice is being slain and the blood of atonement is being sprinkled.