In the old testament (and in many ANE cultures), "name" was a synecdoche for the person, but with the connotation that this is the mechanism by which the person was known. In modern English, we only think of "name" as an identifier with no relationship to the underlying character of the person, and thus many of these "name" references in scriptures are confusing.
Thus when the Angel asked Jacob, "What is your name?", this was not a request for identification, but the Angel was demanding that Jacob confess his nature, that is, that he was a supplanter, as Jacob means "supplanter".
A better sense-for-sense translation for modern readers might be "tell me who you are?" which would carry with it the connotation that this was about your character rather than just a mechanism of identification.
This is why it so profound that God changed the name of Abram and Jacob, as God is effectively changing their character from that point forward. It is a reference to an inward change. We are also promised to receive new names in Revelation 3.12, 2.17. This is also a promise of an inward change. See also Isaiah 62.2
The nations will see your righteousness, And all kings your glory; And
you will be called by a new name Which the mouth of the Lord will
Similarly, to do something "in the name" of someone else was to take on that person's authority and character. Thus praying "in the name" of Jesus does not mean saying "in Jesus' name" as a magical incantation, but it means representing Jesus in the world as we pray, with his authority and character.
So with this background knowledge, if Christ plays the role of "davar" or Word of God, that is, the revelation of YHWH to the world, then to call on the name of YHWH would automatically require calling on Christ, as God's nature (i.e. his name) is revealed to the world only as Christ, and thus Christ's name would be the only "name" that could be called on if one wanted to call on the name of YHWH.
Jesus saith unto him, I am the way, the truth, and the life: no man
cometh unto the Father, but by me. 7 If ye had known me, ye should
have known my Father also: and from henceforth ye know him, and have
seen him. 8 Philip saith unto him, Lord, shew us the Father, and it
sufficeth us. 9 Jesus saith unto him, Have I been so long time with
you, and yet hast thou not known me, Philip? he that hath seen me
hath seen the Father; and how sayest thou then, Shew us the Father?
This passage in John, in the language of "names", says that Jesus was acting in the name of the Father, therefore to call on the name of the Father is to call on the name of Jesus.
Neither is there salvation in any other: for there is none other name
under heaven given among men, whereby we must be saved