Is this a coincidence? I think not. If you make a claim on someone, then you would expect that someone to back your claim up. If I claim somebody is a king, you would expect that king to say he is a king, at least once. In the OT God says he is God several times, why not once with Jesus in the NT? Did God change his ways? I think not, since the OT says God does not change. Here are the passages from the OT where God says he is God:
Gen 35:11 And God said unto him, I [am] God Almighty: be fruitful and multiply; a nation and a company of nations shall be of thee, and kings shall come out of thy loins
Gen 46:3 And he said, I [am] God, the God of thy father: fear not to go down into Egypt; for I will there make of thee a great nation:
Exd 16:12 I have heard the murmurings of the children of Israel: speak unto them, saying, At even ye shall eat flesh, and in the morning ye shall be filled with bread; and ye shall know that I [am] the LORD your God.
Exd 20:2 I [am] the LORD thy God, which have brought thee out of the land of Egypt, out of the house of bondage.
Psa 46:10 Be still, and know that I [am] God: I will be exalted among the heathen, I will be exalted in the earth.
Psa 50:7 Hear, O my people, and I will speak; O Israel, and I will testify against thee: I [am] God, [even] thy God.
Psa 81:10 I [am] the LORD thy God, which brought thee out of the land of Egypt: open thy mouth wide, and I will fill it.
Isa 41:10 Fear thou not; for I [am] with thee: be not dismayed; for I [am] thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness.
Isa 45:3 And I will give thee the treasures of darkness, and hidden riches of secret places, that thou mayest know that I, the LORD, which call [thee] by thy name, [am] the God of Israel.
Isa 45:5 I [am] the LORD, and [there is] none else, [there is] no God beside me: I girded thee, though thou hast not known me:
Isa 46:9 Remember the former things of old: for I [am] God, and [there is] none else; [I am] God, and [there is] none like me,
Jer 32:27 Behold, I [am] the LORD, the God of all flesh: is there any thing too hard for me?
Eze 13:9 And mine hand shall be upon the prophets that see vanity, and that divine lies: they shall not be in the assembly of my people, neither shall they be written in the writing of the house of Israel, neither shall they enter into the land of Israel; and ye shall know that I [am] the Lord GOD.
Eze 20:19 I [am] the LORD your God; walk in my statutes, and keep my judgments, and do them;
Eze 20:20 And hallow my sabbaths; and they shall be a sign between me and you, that ye may know that I [am] the LORD your God.
Eze 23:49 And they shall recompense your lewdness upon you, and ye shall bear the sins of your idols: and ye shall know that I [am] the Lord GOD.
So as we can see, God is not shy to say I am God. SO if Jesus is God, then how come he never said it once like the God of the OT? This is not a coincidence.