In Naruto Shippuuden episode 56 Kakashi called Yamato "Tenzou" so that means he is the young boy in the New episode who returned to his clan or not? :erm:
It's likely [in the Fillerverse] that Kinoe figure out he is truly Tenzo [filler] then later uses that as his "code name" with Kakashi [canon] and when he joins Team Kakashi he becomes our lord and savior Yamato.
the problem is....orochimaru planted the senju dna and made his experiments with babies i think...but in his flashback and also according to this video yamato was already at like age 4^^ but meh who cares those fillers are awesome anyways. cant wait to see itachi