Following is the most interesting explanation I have read on the name Jehovah being absent from the Greek scriptures. This from believers of course.
That it was the purpose of YaHWeH of the OT to have the name YHWH go into obscurity. That God was known to the Hebrews and Israelites as Yahweh. But now the true God was to be known to all the world by means of His earthly son. So His purpose changed, that he was no longer just YHWH of the Israelites, but now he was to GOD for all the world. Thus, the name YHWH had finished its purpose. By the time Jeus arrived, the name was known only as a historical reference and was not used in every day worship. Not even by Jesus.