Namco Bandai Games Europe has posted a FAQ on their website officially confirmed the Edo Kage, Kinkaku, Ginkaku, and the six missing Ninja Swordsmen of the Mist will not be playable in the game. They’ve stated it isn’t possible to include them through downloadable content (DLC).
Granted, it's a great game, but they really should have given us more characters than what we got. With it being the 3rd "main" entry into the series.
Not to mention that the trailers were quite misleading. They certainly led me to believe all the Kage were playable. I mean shoot, they had movesets and everything.
Generations 2: Edo Kages
Storm 4: Tobi unmasked and Dragon Kabuto