Half of the named pandas in Wang Wang's family tree don't have repeated names...
I guess its a Chinese language thing, although it seems to be becoming prevalent among those from the southern US, who have spawned such greats as Phillip Phillips...
in Chinese the doubling of the name generally acts as a diminutive (i.e. making the name into a cuter form or a pet name), I guess similar to the way Elizabeth becomes Liz in English. When used for people the doubling of the name is usually used for girls, only sometimes for boys.