According to the LDS Bible Dictionary
“The term arises out of Rev. 12:7 and refers to the conflict that took place in the premortal existence among the spirit children of God….Although one-third of the spirits became devils, the remaining two-thirds were not all equally valiant, there being every degree of devotion to Christ and the Father among them. The most diligent were chosen to be rulers in the kingdom (Abr. 3:22-23). The nature of the conflict, however, is such that there could be no neutrals, then or now (Matt. 12:30; 1 Ne. 14:10; Alma 5:38-40).”
One of the rationales for the priesthood/temple ban was that black people weren’t valiant in the premortal life. This entry notes that some were more valiant, but also notes that there were no neutrals. Does this entry provide justification, or a refutation for the ban?