I am married to a Mormon and am familiar with their teachings one thing
I want to say is Mormons do not shun others in fact many members do not
even know when a member is excommunicated and if they do know they still
associate with them. In all the years I have been married to my wife and attend
many services I have never seen anyone shunned.
I've talked to Mormon missionaries about shunning and got them to admit that it does happen, although they said that it isn't part of their doctrine and it shouldn't be happening. It took them a while to admit to it, so it leads me to believe it happens more ofthen than they are willing to acknowledge.