when i joined the LDS church, while yet Spencer Kimbal was prophet, i was interviewed and asked whether He was the "only" prophet on earth.
i said yes, even though it was only a probability in my mind, and i yet questioned my own answer.
i have come to believe for the most part, that there is INDEED ONLY ONE PROPHET. however, i have also had vision/dreams of other prophets and likewise at least ONE Seer/prophetess. and i know that there are two non mormon prohetesses who have received greater visions than i have yet to see and experience. Betty Eadie is one and marilynn hughs is another, not to forget to mention Helen White. when i read some of the doctrines in the D&C, i find that there is a peculiar verse about Jesus choosing "witnesses" and how he chooses them whomever he will for his own purposes.
while the priesthood is "restored" through Joseph Smith the gifts of prohecy can be, (conclusively given to anyone), yet at the same time there is a waring of false visions and false spirits that also go forth into the world.
why did i share this with you? in order to answer your question!
the LORD i think gives the gifts of prophecy to those that "qualify", to those He LOVEs, and to those that love him. glory is added upon glory whether they be male or female.
I dont think Pres Monson is a "false" prophet, since joseph smith jr was alive, evil men and superstition and fear have always made men to speak either evil or good of any prophet, remember in history, Most TRUE prophets are murdered and the allegations of false witnesses and eevil kings or evil priestcrafts.
since the days of Able, mankind has followed Cain, in the secret societies of secret combinations, Our generation and the entire world is full of "Them" in every nation, whereever lucifer or satan is worshipped.
i believe there is only ONE church that was restored. however, i can appeal to the words of Genesis which say, YOU may eat of any tree except "one". jesus said a few things that are similar, in one event he rebuked his disciples to not rebuke people of other's faith.but He himself would later rebuke the pharisees and the saducees and lawyers alike for being hypocrites and for the false doctrines.
when Jesus appeared to joseph smith, Jesus said, however, NOT to join any of "them" they are all wrong. He even used the word "abomination".
President Monson, in my opinion, may not have had any direct Revelation or visitation of the Lord, that i know of, but he has been part of the general leadership of the church for decades. i dont think he would intentionally Lead anyone astray, if it were up to him. i wouldnt call him a false prophet, nor would i call joseph smith a con-man or a false prophet. i consider the testimonies of His pears to be greater than the testimonies of evil men that lived alongside him, MORE than the whisperings of satan and the slander of an adulterous generation filled with corrupt politicians and murdering Mobs.