I have noticed that when some one joins the Network then there is a msg saying
.............. is now a member of Kanchenjunga Social Network
"them" can refer to one person when the sex of the person isn't known where "him" or "her" would be operative...example: "If anyone touches my plate, I will be upset with them."
you MAY be able to reference it back to the person's name via the language editor, search for the word string, and replace "them" with %1$s and see if that works. in my opinion, repeating the name again so quickly sounds even more canned than "welcome them" , it's too redundant. JMHO.