Even though this reply is soo damn late, I think madara has not noticed sasuke because maybe he is unaware that the uchihas have been slain. I think in one of the chapters when they showed old aged madara he died long b4 the uchiha masacre occured, so when he finally edo tensei he probably still thinks the uchihas are alive, when in fact if hashi said that sasuke is the 2nd last uchiha next to obito he'd be shocked.
