All that means is Ishmael is not part of the seed line. No mention of the Church. Salvation is not in the context. Your private interpretation is wrong. God elected who would fulfill the promise of the seed line.
Ishmael?
Since when was Ishmael a part of Israel?
Oh, never mind. Let me just show you...
Romans 9:6-8
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
7 Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.
8 That is, They which are the children of the flesh, these are not the children of God: but
the children of the promise are counted for the seed.
Galatians 3:7-9
7 Know ye therefore that
they which are of faith, the same are the children of Abraham.
8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed.
9 So then they which be of faith are blessed with faithful Abraham.
Galatians 3:14-18
14 That
the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.
15 Brethren, I speak after the manner of men; Though it be but a man's covenant, yet if it be confirmed, no man disannulleth, or addeth thereto.
16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
17 And this I say, that the covenant, that was confirmed before of God in Christ, the law, which was four hundred and thirty years after, cannot disannul, that it should make the promise of none effect.
18 For if the inheritance be of the law, it is no more of promise: but God gave it to Abraham by promise.
Galatians 3:28-29
28 There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.
29 And
if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.