All series weve heard how cold Madara was but there was really no time to showcase him. A flashback episode would be too short and he would've had to work it in someones story. So as a service to the fans he edo'ed Madara and had him work the 5 Kages just to please us. He could've easily made it someone else but he knew the readers would enjoy it so he hooked us up. Madara must be one of his favorites too. Shout out to Kishi for that

No I just think he want to confirm the first hokages power a little and that's all.