I didn't appreciate that there were Protestant churches that expected this level of detailed doctrinal conformity. The churches I've spent the most time with -- Southern Baptist, Quaker, and Episcopal -- all allow a diversity of belief, within some pretty broad guidelines.
Yes, if you're in that kind of church -- if the pastor expects both bride and groom to be conservative Presbyterians who have affirmed a lengthy confessional statement -- then I can see the pastor rejecting them for expressing dissenting opinions. That's not what I, personally, would want in a pastor or a church, but it makes sense in the context of that kind of church.
Are members who grew up in a conservative Presbyterian church from infancy also expected to affirm the confessional statement? It couldn't be at the time of infant baptism; is there a particular age at which they have to affirm the statement in order to continue in membership?
I'm in the mainline version of Presbyterianism. But from the discussions I've had with members of churches like the PCA, I believe people are reviewed when they formally join the Church, i.e. become voting members. Think confirmation, though that isn't the traditional Presbyterian term. I'm fairly sure the PCA expects people to affirm the Westminster Confession, and to tell the Session any issues they have with it. The Session then judges whether the issue is serious enough to deny membership.
The PCUSA, which is the mainline version of Presbyterianism, asks officers to say they will be guided by the confessions, but not that they agree with every provision. Furthermore, we have a book of confessions, with a range of documents, including the 20th Cent statements that reflect recent theology. When a member joins (or for people growing up in the Church, are confirmed) they are asked only if they accept Christ as Lord and Savior. I think that's more typical Protestant practice.
Remember that Presbyterians are "confessional," meaning that confessions play a central role in how we do theology. So are Lutherans. I don't know Lutheran practice, but I'd guess the conservative Lutheran churches also expect members to agree substantially with the Lutheran confessions.
The PCUSA understands confessional differently. We consider our theology a living tradition, and see confessions as having the dual role of telling the world what we believe and providing guidance for members. Since ours is a living tradition, we expect to continue issuing confessions. Because we have a range of both historical and modern confessions, it would be challenging for someone to affirm all of them in detail. My personal theology follows the modern confessions pretty closely. As for historical influences I follow Calvin's theology more closely than the historical confessions. A lot of us would like to see his French Confession added to the book of confessions.
Because of the natural of confessional Presbyterianism, I think the pastor was well within his rights not to marry people who are at variance with the traditional confessions. My main criticism is that he should have realized this sooner.
My question is broader: whether that kind of doctrinal conformity is appropriate for Christianity. But I have to say that historically it often has been practiced. From fairly early Christianity defined itself by affirming orthodox theology, which was defined by fairly strict standards in key areas such as the Trinity and Incarnation.