No, you have to repeat an action twice yourself, the same event happening by two different people won't work.
Itachi had to repeat the motion of cutting off Kabuto's horn twice, Madara doing any action will have no effect on starting Izanami.
Besides Madara knows far more about the Uchiha then Itachi or Sasuke, Izanami won't work on him.
Itachi had to repeat the motion of cutting off Kabuto's horn twice, Madara doing any action will have no effect on starting Izanami.
Besides Madara knows far more about the Uchiha then Itachi or Sasuke, Izanami won't work on him.