This change in the preposition first appeared in the 1837 edition; it may be the result of Joseph Smith’s editing for that edition, although this change was not marked by him in the printer’s manuscript. For modern readers, the phrase “out from” is definitely more awkward than “out of ”. Nonetheless, the corresponding account in the King James Bible uses the preposition from:
A parallel citation in the Book of Mormon also has from:
Of course, substituting of in place of from would not work as well here in Alma 42:2 (or in Genesis 3:23) since the preceding word is forth rather than out.
There are occurrences of the phrase “out from” which have not been replaced in the Book of Mormon text by the much more frequent “out of”. Consider these examples where of could replace from:
The general lack of textual change in these examples of “out from” suggests that there is nothing wrong with this expression and that it should be restored in 2 Nephi 2:19. In fact, the 1837 change may well be a typo rather than the result of conscious editing. (For another example where out from was accidentally set as out of, see 1 Nephi 3:13.)
Summary: Restore the original reading “out from” in 2 Nephi 2:19; there are quite a few examples of “out from” elsewhere in the text.