If u r talking abt naruto anime d answer would be never.
Fillers rulez in anime.
and abt naruto manga i think after d jubi is over der could be another arc due 2 my assumption it would bring characters like kakashi mom or some background abt her bcus kishi has always shown characters whose names have arisen even though they r dead.eg:7 Swordsmen of d Mist, White Fang,all the previous hokage and edo tensai stuff etc.