GT Essay states "the precise nature" of eternal polygamy "is not known."
"Plural Marriage in Kirtland and Nauvoo," Gospel Topics Essay, accessed Sept. 13, 2021
Church members no longer practice plural marriage. Consistent with Joseph Smith’s teachings, the Church permits a man whose wife has died to be sealed to another woman when he remarries. Moreover, members are permitted to perform ordinances on behalf of deceased men and women who married more than once on earth, sealing them to all of the spouses to whom they were legally married. The precise nature of these relationships in the next life is not known, and many family relationships will be sorted out in the life to come. Latter-day Saints are encouraged to trust in our wise Heavenly Father, who loves His children and does all things for their growth and salvation.