US Immigration from Myanmar

Is there anyone from MYANMAR? I married US citizen 2 and half year ago and now I'm in US with my husband for over 1 year. We filed visa for my son and now the case is at NVC. I have some questions for embassy interview. I divorced my ex-husband (my son's father) in 2006 and he passed away before I remarried to my current husband. I have both certificate of divorced and death, but I heard people are saying that consular might ask permission letter from grand parents to allow my son to come to USA. That will not be easy for me to get since I lost contact with that side so long ago. Can someone share experience with me,please? I need to know those people who recently took embassy interview at US embassy Yangon, Myanmar, thanks in advance.