Board Thread:Theories and Speculation/@comment-28939725-20161201164545/@comment-25122992-20161204194719

Actually, almost everyone could know since Katsuyu was the main informer of Naruto after the Pain's attack and she could deliver the info to others through her multiple pieces. Also, it was enough to know only for Naruto/Kakashi/Guy because they were the opponents of Obito in personal battle, the fight against Shinobi Alliance included Ten-Tails on Obito's side and then its power as a TTJ, so there was no need in the abilities of the lower class when he had much more advanced tools to use.