So what if the next appointed Hokage is a Edo Hokage like Hashi is made Hokage again if he freed himself from the Edo like Madara did could he be Hokage again that would be awesome. Unless he didnt want to I guess
Sir, is your name Kishimoto?O_O
This would never happen, even if the Edo's had control over their own bodies they would want to be released back to the Narutoverse's afterlife.