the New Translation could be many things

To regard the New Translation as a product of divine inspiration given to Joseph Smith does not necessarily assume that it be a restoration of the original Bible text. It seems probable that the New Translation could be many things. For example, the nature of the work may fall into at least four categories:
1. Portions may amount to restorations of content material once written by the biblical authors but since deleted from the Bible.
2. Portions may consist of a record of actual historical events that were not recorded, or were recorded but never included in the biblical collection.
3. Portions may consist of inspired commentary by the Prophet Joseph Smith, enlarged, elaborated, and even adapted to a latter-day situation. This may be similar to what Nephi meant by “likening” the scriptures to himself and his people in their particular circumstance. (See 1 Nephi 19:23-24; 2 Nephi 11:8.)
4. Some items may be a harmonization of doctrinal concepts that were revealed to the Prophet Joseph Smith independently of his translation of the Bible, but by means of which he was able to discover that a biblical passage was inaccurate.


"A Plainer Translation": Joseph Smith's Translation of the Bible, a History and commentary, by Robert J. Matthews. Brigham Young University Press. 1975. p.253