The angel had no name at all until 1835. In his lifetime, Joseph Smith, Jr. always used the name "Nephi" for the angel with one exception. In the Elder's Journal of The Church of Jesus Christ of Latter Day Saints, vol 1, no 3., p 42 (Jul, 1838), he refers to the angel as "Moroni." That's it. If any scholar is aware of any other contemporaneous use by Smith of Moroni during his lifetime, I'd like to know. Joseph Smith, Jr. used "Nephi."
"Moroni" was used by Oliver Cowdry once when Smith was alive and Moroni was used by others after Smith's death. Changes were made to some publications after Smith's death to change Nephi to Moroni.
I'm not talking theology here, I'm talking academics.
LDS Historian Richard L. Anderson admits that the change was made in Pearl of Great Price to Joseph Smith's handwritten use of the name Nephi. He said it was necessary to be consistent with Smith's other uses. However, he doesn't cite any other use by Smith. And to my knowledge no scholar, LDS or non-LDS, has found any use by Joseph Smith of Moroni other than in that Elder's Journal. Once he gave the angel (or ghost, but that's another matter) a name, Joseph Smith, Jr. consistently said the name of the angel who visited him was Nephi. Any other attributions to Joseph Smith are to changes made to writings after his death, such as the change to Pearl of Great Price that Anderson acknowledges, or the change to Lucy Mack Smith's Biographical Sketchesunder the order of Brigham Young (the destruction of the 1853 edition at Young's order is noted in the Deseret News, as noted above).
So the people making the changes were prophets or something? They had authorization from who/whom to make them? Still Joe wrote three different versions of the BOM translation.