I have a "little" problem with Dr. Michael Brown and the Hebrew Roots movement, but will listen to the video you posted.
The promises made to Israel regarding physical promises were based on a conditional old covenant - IF they obeyed, THEN the promises would be theirs. It was a national covenant. The only promise to "Israel" in the New Covenant aka ALL believers in Christ, is the Holy Spirit and eternal life. This is pointed out in Heb 11 and Gal 3.
The New Covenant in Christ, fulfilled the old covenant - it was no longer valid. Therefore; there is no national covenant with Israel. BUT - Israel or the Jews are grafted into Christ via the New Covenant, IF they accept Him as Messiah - not by the nation, but by the individual. As Eph 3 explains, we are one NEW MAN in Christ. There is neither Jew or Greek/gentile in Christ. A physical nation no longer has special favor with God, but only individuals in the blood of Christ.
When Paul speaks of "all Israel" will be saved, he is referring back to chap 9.
"Not as though the word of God has taken none effect. For they are not all Israel, which are of Israel: Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall your seed be called. 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." (Rom 9:6-8)
It is the Hebrew Roots people that accuse others of Replacement Theology.
Accusing people of being guilty of "replacement theology" is tantamount to claiming that someone is "anti-semitic" in HR circles. The idea is that if you believe that you have replaced the Jews you must hate them. It is a total kanard. I have been accused of it in my dealings with the HR crowd. I am "New Covenant". I love Jews, I love all people. I just don't like people who try to manipulate me by accusing me of being guilty of "replacement theology" and a closet anti-semite. HR is indeed a cult. It is sad to see Michael Brown trapped inside but he made his own prison.
The New Covenant to Judah and Israel is explained in the NT as to both Jews and gentiles. True Israel, according to Paul, are those who believe in Christ by faith - this is the inheritance of Abraham [Rom 9,10,11 and Gal 3]. It is no longer a physical nation, but a spiritual, holy nation of believers in Christ [1 Peter 2:9 and Eph 2].
The church [the body of Christ] includes all those who are believers ------ past, present, future, OT and NT. The "church" has not replaced Israel. All Jews who accept Christ are part of the church - that is the promise of Jer 31. Paul explains this as the mystery hid from the ages past. There is neither Jew nor Greek in Christ Jesus.
"This is that Moses, which said unto the children of Israel, A prophet shall the Lord your God raise up unto you of your brethren, like unto me; him shall ye hear. This is he, that was in the church in the wilderness with the angel which spake to him in the mount Sina, and with our fathers: who received the lively oracles to give unto us: To whom our fathers would not obey, but thrust him from them, and in their hearts turned back again into Egypt," (Act 7:37-39)
"Now to him that is of power to stablish you according to my gospel, and the preaching of Jesus Christ, according to the revelation of the mystery, which was kept secret since the world began, But now is made manifest, and by the scriptures of the prophets, according to the commandment of the everlasting God, made known to all nations for the obedience of faith:" (Rom 16:25-26)
"Whereby, when ye read, ye may understand my knowledge in the mystery of Christ). Which in other ages was not made known unto the sons of men, as it is now revealed unto his holy apostles and prophets by the Spirit; That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel: Whereof I was made a minister, according to the gift of the grace of God given unto me by the effectual working of his power. Unto me, who am less than the least of all saints, is this grace given, that I should preach among the Gentiles the unsearchable riches of Christ; And to make all men see what is the fellowship of the mystery, which from the beginning of the world hath been hid in God, who created all things by Jesus Christ: To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God," (Eph 3:4-10)