No, the missionary work of that day will be based in Jerusalem, led by the 144,000 and their fellow members of the Church of the Firstborn. They will be preaching the way Alma the Younger did under similar circumstances later in his life. They will teach not only Faith, Repentance, and Baptism, but how to have the baptism of Fire and the Holy Ghost, how to have the fruit of the tree, not just the seed. What's more, they will be impervious to weapons, as death cannot stop them. Poisons will have no effect, and the famines will bother them only a little. These will be stalwart members of the Church of the Firstborn, not recent converts into its ranks.