What name was unknown?

What name was unknown? Exo 6:3 RNKJV And I appeared unto Abraham, unto Isaac, and unto Jacob, by the name of El-Shaddai, but by my name YHWH was I not known to them? Some try to make this a question, like: wasn't I known to them? Yet the Hebrew does not make this such an emphatic question, which would have been preceeded by a heh ה. Lacking any evidence of this conclusion, we dig further. Gen 15:7 RNKJV And he said unto him, I am YHWH that brought thee out of Ur of the Chaldees, to give thee this land to inherit it. Gen 21:33 RNKJV And Abraham planted a grove in Beer-sheba, and called there on the name of YHWH, El-olam*. Gen 22:14 RNKJV And Abraham called the name of that place YHWH-Yireh: as it is said to this day, On the mountain YHWH provides. Gen 26:25 RNKJV And he builded an altar there, and called upon the name of YHWH and pitched his tent there: and there Isaac's servants digged a well. Gen 28:13 RNKJV And, behold, YHWH stood above it, and said, I am YHWH Elohim of Abraham thy father, and the Elohim of Isaac: the land whereon thou liest, to thee will I give it, and to thy seed; Gen 28:16 RNKJV And Jacob awaked out of his sleep, and he said, Surely YHWH is in this place; and I knew it not. Gen 28:21 RNKJV So that I come again to my father's house in peace; then shall YHWH be my Elohim: So if יהוה introduced Himself to the Patriarchs by his name יהוה, and the Patriarchs call upon the name of יהוה, then what exactly about The name was unknown to them? Israel seems to leave a clue! Gen 49:18 RNKJV I have waited for thy salvation, O YHWH. Yet does Moses introduce יהוה in a entirely new way? Exo 15:2 RNKJV YaH is my strength and song, and he is become my salvation: he is my El, and I will prepare him an habitation; my father's Elohim, and I will exalt him. Moses is the first to use the name of Yah, and to reveal how this name relates to our personal Salvation, our Yeshuah/Yeshua. The name of Yah begins with Ex 3:14; not as the I am who I am, but rather as the singular I am who went with Moses. Exo 3:14 RNKJV And Elohim said unto Moses, I AM THAT I AM: and he said, Thus shalt thou say unto the children of Israel, I AM hath sent me unto you.