Care to expound on that a bit?
If this article is correct, these Amish have adopted the dispensational nonesense about "replacement theology." Such an idea never existed prior to John Darby, the Nineteenth Century founder of dispensationalism. The term "replacement theology" is a false, pejorative insult against traditional Christianity.
The Jews who followed their prophesied Messiah were not "replacing" anybody. They remained faithful to God as they founded the Church and eventually brought in the Gentiles. Unbelievers were not God's people in the Old Covenant, so their status has not changed.
1 Peter 2:9 "But ye are a chosen generation, a royal priesthood, an holy nation, a peculiar people;"