In 1876, Orson Pratt added a footnote that was later removed by the Church in 1909. I believe the footnote was in 2nd Nephi, chapter 3, verse 24. In the very beginning of the verse we read of “One mighty,” who Orson Pratt implies by a footnote that it will be an Indian prophet. Was this changed simply because Orson Pratt was wrong?
There is very scant but intriguing evidence that early Church members did believe a prophet would arise from among the Native Americans. Very early in the Church’s history, one journalist observed that Oliver Cowdery was embarking on a “mission to the Indians (or Lamanites, as they term them) in the ‘far west,’ where they say a Prophet is to be raised up, in whom the tribes will believe.” (Source: Juvenile Instructor » Early Mormon Lamanism, Forgotten Apocalyptic Visions, and the Indian Prophet).
The current LDS edition of the Book of Mormon is copiously cross-referenced, but it takes a minimalist approach with regard to footnotes that define or explicitly clarify particular passages. The fact that the Church no longer emphasizes the idea of a future Native American prophet doesn’t mean the notion is wrong; it just means that the actual evidence supporting the notion is inconclusive.