Compared to who?
and have traditionally been firm proponents of Replacement Theology, which claims that God cast aside the Jews for their widespread rejection of Jesus as their messiah.
As were pretty much all Christians at one point.
Many Amish once believed the Nazi Holocaust was Gods punishment for that rejection of Jesus, and actually applauded Hitler.
Many? How do we know?
It would be surprising if a group of German ancestry didn't have some sympathy with Germany in the 1930s, but I'd have to know a lot more about the background before accepting the author's claims as fact.
The pejorative term "Replacement Theology" did not exist among Christians prior to Nineteenth Century dispensationalist heretic John Darby.