Board Thread:Questions and Answers/@comment-39522398-20190519202509/@comment-31222592-20190925194259

That doesn't make much sense. What the Hollow meant, he clarified immediately afterwards. He is Zangetsu because he & old man Zangetsu are one & the same. These aren't the ramblings of an insane Hollow, this was immediately explained & accepted by Ichigo then & there. It was further reinforced when Tensa Zangetsu & the Hollow fused together & said so again.

This also wasn't foreshadowed, it was contradicted & even this article admits that the Hollow & old man are the same in

Zangetsu has access to the Shinigami powers that inherently belong to Ichigo due to being one with Ichigo's true Zanpakutō spirit/Inner Hollow

So the "real" Zangetsu was always the old man & the Hollow together, because both are one & the same. Saying the old man was never the real one, & that the Hollow is the real one, is alike saying X is & X isn't at the same time or like saying Bruce Wayne is & Batman isn't.