The "conspiracy" is always an over exaggerated form of the claim, so that it can be "debunked." Hellen Keller was a real person, who was really deaf and blind, but she wasn't actually communicating. She was performing like a trained animal, unaware of what words she was approximating. Those all came from Anne Sullivan, using Keller as a front to promote her ideas.

Here's the real "conspiracy," but what you see when you do a google search is teenagers claiming she never existed, or wasn't really blind because taking down a straw men is all these "fact checkers" are about: https://www.youtube.com/watch?v=5UMDG_qH_RU