anyone ever have a family member disappear and did they ever come back?

my father's cousin has a son that has disappeared for yrs, about two months ago i tried looking him up on facebook and asked if he was the same person that has this name and his mother's name, two months later he writes me back and says yes, i gave him his mom's number and now im wondering if hes going to call her, he had his work email there too so i sent him a message there too since it takes him too long to respond on facebook, now im wondering if he'll call her, i talked to her today and told her about it, it'll be interesting to see if he does call