Its an interesting question. I have no particular opinion on it. "Sons" can be a generic term, because all sisters in the Lord are also "sons of God" as a descriptive term for the overcomers in Christ. Jesus said that in the resurrection we will be like the angels, not giving or being given in marriage. Some folks believe that means angels have no gender, but i am not sure about that. It is interesting that the names we have are male names..... Michael, Gabriel...are there any others?