If the eternal Son of God had remained in heaven (as the Word of God, who is God, and who made everything that was made John 1:1-3), the matter of inheritance would never have arisen. It only arose because a usurper arose, intent on wresting away from God control over his creation. He involved heavenly creatures (like himself) in the attempted coup, so it wasn't just the material creation that was involved.
The entire material creation of God started to become contaminated with the sin introduced ("All creation groans..." Romans 8:22). As God is too pure to look upon sin, had not God started to enact his plan of redemption which was formed before any creation started, all of that material creation would have been lost. The coup would have succeeded. Evil would have corrupted and ruined it all. But we know that God's plan of redemption was mentioned in the garden of Eden (Genesis 3:15). At just the right time, while we were helpless, human nature was added to the Son of God, who retained his divine nature, and entered our stricken world as Jesus. Trinitarians speak of that as "the incarnation".
That is why Jesus was able to say he saw Satan fall like lightning at a certain time (Luke 10:18). Heaven was cleansed of satanic, demonic beings. God remained sovereignly in control, and had never at any time relinquished his sole rights to creation. Everything the evil one does as "god of this world" is deception, and he knows his time is short. He knows what awaits him and his hordes when Christ the King suddenly returns in glory to usher in the Day of Resurrection and Judgment.
That is when "a new heavens and a new earth, in which righteousness dwells" shall replace the present corrupted set-up (Isaiah 65:17 cf. 2 Peter 3:10-13).
This preamble is necessary to show why the Son of God was promised to become heir of all things. He had to lower himself, to leave his glory in heaven and become a servant on Earth. Then, having done the will of the Father, return to the glory he once had and the promise then be fulfilled. That is why he prayed the following things before entering Gethsemane:
"And now, O Father, glorify thou me with thine own self with the glory
which I had with thee before the world was... Father, I will that they
also, whom thou hast given me, be with me where I am; that they may
behold my glory, which thou hast given me: for thou lovedst me before
the foundation of the world." John 17:5 & 24 A.V.
A return to that glory had been promised the Son, he agreed to be sent into the world in full faith that the Father would keep that promise, and Hebrews 1:2 confirms all that. But if the plan of redemption had not been formed prior to any creating starting, there could have been no letter to the Hebrews telling us that, nor the gospel of John with those bits quoted here, nor any other books of the New Testament, nor any books of the Old Testament, for creation would have been usurped; wrested away from God by deceit. But what kind of a god would not have foreseen that and prepared for the legal condemnation of the illegal would-be-usurper? God is God, and knows all things, and will yet transform all creation to glory untarnished - "a new heavens and a new earth, in which righteousness will dwell".
The eternal Father and the eternal Son and the eternal Spirit are bound up together from the planning of, and the execution of, this turning back to initial pure glory and sinlessness, which is what Hebrews 1:2 hints at, enlarging on this theme before the chapter ends:
"And thou, Lord, in the beginning hast laid the foundation of the
earth; and the heavens are the works of thine hands. They shall
perish; but thou remainest; and they all shall wax old as doth a
garment; and as a vesture shalt thou fold them up, and they shall
be changed: but thou art the same, and thy years shall not fail. But
to which of the angels said he at any time, Sit on my right hand,
until I make thine enemies thy footstool?" Hebrews 1:10-13 A.V. bold
emphasis mine.
1 Chronicles 29:11 is clearly addressed by king David to "the Lord God of Israel". Verse 10 states that. Only those confused into wrongly thinking that the term "God the Son" means a second god, distinct from the Lord God of Israel, would ask the questions posted in the last paragraph here. The totality of God is involved in total creation, and the totality of the Son is involved in total creation, which is why John 1:1-3 was invoked in the opening paragraph of this answer.
