What can I say but my thoughts are with you. Like you, religion is a no go area with my family and both sides respect the stand off. I know the feeling when an important decision is made and your left out of loop screaming silently but as of yet not as major as your predicament. I know though it is one I may have to face.
Get the facts on the operation and get the facts on what your family are going to do regarding the present of a hospital liaison committee. Tell them how you feel about the situation before it happens. Not talking about religion and having accepted you, your husband and your son, it sounds to me like they put a lot of value on family regardless of the org. In the end it will be his decision but that shouldn't stop you voicing your opinion if an group of old men who care more about how it would look to others have the right to voice theirs. Never let the org dominate you into submissiveness again.