Board Thread:Naruto Discussions/@comment-29393962-20161111215453/@comment-25122992-20170117141724

Reanimations can be only "rejuvenated" in sense of removing the most of the defects of the reanimated body (like zombi-like appearance), but it's limited to their lifetime appearance, so it doesn't include the actual age modification. Hiruzen stated that Oro made the First and the Second look exactly as he remembered them to look, and Hiruzen knew the both up to their deaths, which means he remembered their pre-death appearance as well. They weren't that old at the point of their death, and Oro didn't make Hashi look as yound as he was during the VoTE battle, after all. So it's not a usual thing for Edo Tensei user to tamper with the state of the reanimated body. Otherwise, Kabuto could've easily restored a whole bunch of shinobi if not all of them to the desired state of their "prime", yet he mentioned that only Madara was "special" in this regard.