Why didn't Naruto and Sasuke feel a disruption in their chakra when Madara and Hashirama were reanimated?
Yes but no, one because they don't feel a disruption in their chakra, but in general, as long as Naruto or Sasuke had some form of sage mode enabled, then sage mode would allow them to sense a strong appearance of chakra. Naruto would be able to sense all the Kage as well as Sasuke and all the Edo Tensei, ever sense the war ark started... so PLOT HOLE.