Imo, from the standpoint of religious history, the name Yhwh was practically bound to disappear as an embarrassing vestige of polytheism.
It was very natural for Yhwh to be called by his name in everyday life when he was thought of as one god among many. E.g. Judges 11:23f:
So now Yhwh, the god of Israel, has conquered the Amorites for the benefit of his people Israel. Do you intend to take their place? Should you not possess what your god Chemosh gives you to possess? And should we not be the ones to possess everything that our god Yhwh has conquered for our benefit?
However, when Yhwh became "God," the only one, this traditional function of his name became meaningless. It had either to be dropped altogether or theologised up/away, for instance as "being" (Exodus 3:14f). In monotheistic Judaism it actually became a most holy name, too holy to be uttered out of a fixed liturgical frame, and at the same time a dangerous and powerful tool in underground magical uses.
The stance of the Greek-speaking Jew Philo of Alexandria, in the early 1st century AD (before the NT) is quite enlightening in this respect (On the Change of Names):
II. (7) Do not, however, think that the living God, he who is truly living, is ever seen so as to be comprehended by any human being; for we have no power in ourselves to see any thing, by which we may be able to conceive any adequate notion of him; we have no external sense suited to that purpose (for he is not an object which can be discerned by the outward sense), nor any strength adequate to it: therefore, Moses, the spectator of the invisible nature, the man who really saw God (for the sacred scriptures say that he entered "into the Darkness,"{3}{#ex 20:21.} by which expression they mean figuratively to intimate the invisible essence), having investigated every part of every thing, sought to see clearly the much-desired and only God; (8) but when he found nothing, not even any appearance at all resembling what he had hoped to behold; he, then, giving up all idea of receiving instruction on that point from any other source, flies to the very being himself whom he was seeking, and entreats him, saying, "Show my thyself that I may see thee so as to know Thee."{4}{#ex 33:13.} But, nevertheless, he fails to obtain the end which he had proposed to himself, and which he had accounted the most all-sufficient gift for the most excellent race of creation, mankind, namely a knowledge of those bodies and things which are below the living God. (9) For it is said unto him, "Thou shalt see my back parts, but my face shall not be beheld by Thee."{5}{#ex 33:23.} As if it were meant to answer him: Those bodies and things which are beneath the living God may come within thy comprehension, even though every thing would not be at once comprehended by thee, since that one being is not by his nature capable of being beheld by man. (10) And what wonder is there if the living God is beyond the reach of the comprehension of man, when even the mind that is in each of us is unintelligible and unknown to us? Who has ever beheld the essence of the soul? the obscure nature of which has given rise to an infinite number of contests among the sophists who have brought forward opposite opinions, some of which are inconsistent with any kind of nature. (11) It was, therefore, quite consistent with reason that no proper name could with propriety be assigned to him who is in truth the living God. Do you not see that to the prophet who is really desirous of making an honest inquiry after the truth, and who asks what answer he is to give to those who question him as to the name of him who has sent him, he says, "I am that I Am,"{6}{#ex 3:14.} which is equivalent to saying, "It is my nature to be, not to be described by name:" (12) but in order that the human race may not be wholly destitute of any appellation which they may give to the most excellent of beings, I allow you to use the word Lord as a name; the Lord God of three natures--of instruction, and of holiness, and of the practice of virtue; of which Abraham, and Isaac, and Jacob are recorded as the symbols. For this, says he, is the everlasting name, as if it has been investigated and discerned in time as it exists in reference to us, and not in that time which was before all time; and it is also a memorial not placed beyond recollection or intelligence, and again it is addressed to persons who have been born, not to uncreated natures. (13) For these men have need of the complete use of the divine name who come to a created or mortal generation, in order that, if they cannot attain to the best thing, they may at least arrive at the best possible name, and arrange themselves in accordance with that; and the sacred oracle which is delivered as from the mouth of the Ruler of the universe, speaks of the proper name of God never having been revealed to any one, when God is represented as saying, "For I have not shown them my Name;"{7}{#ex 6:3.} for by a slight change in the figure of speech here used, the meaning of what is said would be something of this kind: "My proper name I have not revealed to them," but only that which is commonly used, though with some misapplication, because of the reasons abovementioned. (14) And, indeed, the living God is so completely indescribable, that even those powers which minister unto him do not announce his proper name to us. At all events, after the wrestling match in which the practicer of virtue wrestled for the sake of the acquisition of virtue, he says to the invisible Master, "Tell me thy Name;"{8}{#ge 32:29.} but he said, "Why askest thou me my name?" And he does not tell him his peculiar and proper name, for says he, it is sufficient for thee to be taught my ordinary explanations. But as for names which are the symbols of created things, do not seek to find them among immortal natures.
Of course this development was regarded as providential by several segments of early Christianity, as shown by the Pauline use of
kurios ("Lord," Romans 10:9ff; 14:8f) and the Johannine use of
egô eimi ("I am," John 4:26; 8:24,28,52 etc.)
as applied to Jesus.
