It could have appeared in the JST; couldn't it??
Exactly!
Why Smith supposedly was putting back into place stuff removed from the Bible in his JST version...even adding & changing over 100 words in the book of Revelation...a big "no-no"
18 For I testify unto every man that heareth the words of the prophecy of this book, If any man shall add unto these things, God shall add unto him the plagues that are written in this book: 19 And if any man shall take away from the words of the book of this prophecy, God shall take away his part out of the book of life, and out of the holy city, and from the things which are written in this book.
(Rev. 22:18-19)
Surely, if Smith was willing to put heaven on the line in his messing with the Book of Revelation, he could have "restored" all those books the Mormons feebly allege the Christians took out of the Scriptures!