Decrees of God Unalterable
Alma 41:8; “Now, the decrees of God are unalterable; therefore, the way is prepared that whosoever will may walk therein and be saved.”
Mormon Doctrine, pg. 527; “In all past ages and until recent times in this dispensation, the Lord did not offer the priesthood to the Negroes. However, on June 1, 1978, in the Salt Lake Temple, in the presence of the First Presidency and the Council of the Twelve, President Spencer W. Kimball received a revelation from the Lord directing that the gospel and the priesthood should now go to all men without reference to race or color.”
This serves as just one example of how the god of Mormonism does indeed change his mind and therefore qualifies as a false prophecy.