****The CC most certainly thinks they have replaced Israel.***
That is not Replacement Theology. The passage never says that the Church has replaced Israel.
The use of the word collegial here demonstrates what the Church believes is our relationship to Israel. Just as Scripture tells us that we are now coheirs...
Ephesians 3 Brothers and sisters: You have heard of the stewardship of God’s grace that was given to me for your benefit, namely, that the mystery was made known to me by revelation. It was not made known to people in other generations as it has now been revealed to his holy apostles and prophets by the Spirit: that the Gentiles are coheirs, members of the same body, and copartners in the promise in Christ Jesus through the gospel.
***the seeds of the new Israel***
The new Israel is the community of ALL believers, whether Jew or Gentile bound together under the New and Everlasting covenant which is Jesus Christ.
Those Jews living under the old covenant, while still heirs to the promises of God, have chosen to remain in the old rather than believe in Jesus. They are not part of the Church and they still exist, they have not been replaced.
See 1267. Trying to explain what we believe to people who think we are pagan idolators may be asking too much of their own prejudiced worldviews.
Not understanding what replacement theology is no excuse for denying it.