Well, more specifically, how does the story of Krishna fit into the Baha'i interpretations? Like him being a manifestation but not an incarnation of a God? Like he spoke for the One True God and was not part of a polytheistic Godhead? Like a manifestation brings new social teachings and affirms the same eternal spiritual teachings? Since Baha'is don't believe in reincarnation, did you find some more things to support your belief that Krishna didn't actually teach reincarnation? And, how can Hinduism not have a manifestation as its founder?
The Baha’i understanding of Krishna is that He was a real person who lived amongst men but was also a Manifestation of God. What is clear from the Purana and Gita is we have mythologised history. We’re talking about someone who lived five thousand years ago. So we.can’t say too much for certain. Five thousand years ago is not too far from six thousand years ago when the Prophet Adam lived. So look at how mythological that story becomes in Genesis. Beyond Adam the accurate historicity of any character essentially becomes so obscured as to be meaningless. That’s religion and it eventually fades as the old gives way to the new.
So with Hinduism, the Baha’i writings don’t say much apart from its a religion of Divine origins, reincarnation is not a literal transmigration of souls, and there is One Supreme Being. Basically we can’t prove or disprove anything. Hindus have clearly abandoned any attempt to portray a unified truth in their religion. As said repeatedly, its a very different paradigm from the Abrahamic Faiths.