Matthew names Jesus son of David. The throne promise of 2 Samuel 7 does not wait for a later earthly administration.
David was promised a son whose throne God would establish. Psalm 2 and Psalm 110 supply the court language: the nations rage, the Son is set on Zion, enemies become a footstool. Acts reads those psalms as already happening in the resurrection and exaltation.
A throne “in heaven” is not a consolation prize. In Hebrew world-order language, heaven is the seat of government. The King rules from there over the earth.
Matthew’s genealogy is a legal brief for kingship. The Magi ask for the King of the Jews. The passion mocks a king — and heaven answers by raising Him. Matthew 28 then gives all authority in heaven and on earth to the risen One.
The book is not waiting to start the reign. It shows the rightful heir taking the throne while the old city still stands, then judging that city when it refuses Him.
First-century rulers — Herodian, priestly, and Roman — are the raging kings of Psalm 2 in history. The collapse of the old covenant authorities in that generation is the public outworking of an already-installed reign.
The Son is enthroned. New Creation life is life under a present King, not life in a waiting room.