RLDS scholar L.E. Hills decided that Joseph Smith, Oliver Cowdery, and their successors in the LDS church were wrong about Cumorah in New York. He rejected Letter VII and the teachings of Brigham Young, Heber C. Kimball, Orson Pratt, and every other LDS leader who ever addressed the topic.
Hills published a map in 1917 showing Cumorah in southern Mexico.
|L.E. Hills 1917 map
Over the objection of LDS leaders, LDS scholars copied the map published by L.E. Hills, moved Cumorah a few miles east, called it their own, and published it everywhere, including on the BYU Studies web page, where you can still see it today.
|BYU Studies map
Church leaders asked the scholars to stop teaching a specific geography, so CES took the BYU Studies map and turned it into a fantasy map, continuing to teach students that the prophets were wrong about Cumorah in New York.
|CES fantasy map
Book of Mormon Central continues to insist that the only viable and permissible interpretation of the text is M2C. They've embedded M2C in their logo by using a Mayan glyph to represent the Book of Mormon.
Nevertheless, some people wonder why faith in the Book of Mormon is declining, both among young people who are taught this fantasyland version of the Book of Mormon and among nonmembers contacted by the missionaries (who have been taught M2C).
For more info, see http://www.lettervii.com/2017/12/lessonfireside-material.html