I'm going to go on now before this thing gets rolling and point out that the PCUSA is a very liberal organization, much like the Democratic Party while Presbyterian Church of America consists of believing Christians who are conservative in their moral values and (more than not) their politics. Please don't lump all Presbyterians together.
I would add on to this comment and also point out that there is a substantial and growing number of PCUSA churches comprised of believing Christians who have joined the "Confessing Church Movement," which seeks to turn back the revisionists in PCUSA.
Needless to say, they take a dim view of anti-Semitic teaching such as appears in this article. The argument that the Jews were made unnecessary and discarded by God in the New Testament has been the rationale for anti-Jewish pogroms and the holocaust. The statements in this article are not quite that strong, but that is the ultimate logic that underlies them.
There are many believing Christians even in PCUSA. The problem is the leadership and national bureacracy have been taken over by left-wing seminary graduates whose goal is to merge the PCUSA with the even more liberal UCC (United Church of Christ). As such, they reflect the growing anti-semitism of the Left.