I'll agree about the changes in affiliation being generally unimportant in practice and culture. Though that's not very theologically sound, either. We can leave that to the side other than to say that reconciliation, forgiveness, and unity are clearly commanded in the Bible.

I was more concerned about the more popular misconception about protestant Christianity: that it mostly involves claiming a label then going to heaven. This does a lot of harm because a lot of "Christians" are more or less untrained, unaccountable, and frankly bad people. And they are the examples often brought up when discussing hard feelings and distaste for Christianity.

I'd also wouldn't blame predestination for the lack of stress on membership and the consequential toothlessness of shunning. It more has to do with the removal of actual priests (i.e., with collars and robes) from any sort of essential role. You don't have to make any particular clergyman or bishop happy to have a birth blessed, a holy funeral, an honorable wedding, or salvation itself.