If the court sanctions gay marriage it would most likely make it illegal to refuse to perform or deny the of your church for the “weddings”. It will also lead to a legal ban on preaching about the biblical passages condemning sodomy as a sin.
To refuse to obey could mean jail time and/or hefty fines as is already happening in Norway. It is not a small thing for these pastors to issue this statement.
Over a sinful lifestyle choice?