Shunning, in those sects that still practice it, generally isn't a permanent affair, nor was is originally specified to be. The shunning isn't the problem for you and I, its that lgbtq lifestyles are usually(depends on the community - even among the amish) a "living in sin"/shunnable affair no one should have to repent or hide.
EDIT: Jesus Christ, Amish shunning for rape and icest is only six weeks, AND they forbid reporting of such crimes to law enforcement? WTF?
Noting that aiding and abetting a crime, including lying to hide another's crime, and the intimidation of witnesses and victims, are all well-established secular law, there is no grounds for how too many religious communities handle such things. Priests and Pastors should be mandatory reporters, not privileged to keep confidentiality where serious crimes are concerned, nevermind that these people are openly confessing to their entire congregations/communities.