It should read John was not "martyred."
Nope. If you go to the Lds add-on "scriptures" -- what they call "Doctrines & Covenants"... you'll find their intro to Section 7 clearly focuses on whether John died:
Section 7
Revelation given to Joseph Smith the Prophet and Oliver Cowdery, at Harmony, Pennsylvania, April 1829, when they inquired through the Urim and Thummim as to whether John, the beloved disciple, tarried in the flesh or had died.
Source: D&C 7
6 And he said unto them: Behold, I know your thoughts, and ye have desired the thing which John, my beloved, who was with me in my ministry, before that I was lifted up by the Jews, desired of me. 7 Therefore, more blessed are ye, for ye shall never taste of death; but ye shall live to behold all the doings of the Father unto the children of men, even until all things shall be fulfilled according to the will of the Father, when I shall come in my glory with the powers of heaven. (3 Nephi 28:6-7, Book of Mormon)
So not only does the official Mormon church teach that the apostle John's been "hangin' 'round" all these centuries, but that he could have been "linkin' up" with these Book of Mormon times Nephite entourage!
With all of these "No Coffin Zone" Mormons on the loose, at large, wonder why Joey Smith ever illusioned that he was somehow necessary as a 14-yo pimple-faced kid to jumpstart "the only true and living church on the face of the earth" (Lds "scriptures" -- D&C 1:30)????