In 1912 some Mormon leaders doubted both the content and reliability of The King Follett Sermon. Mormon apostle George Albert Smith wrote:

“Sometime ago I received an invitation, mailed from the Liahona office, to contribute to a fund for the purpose of mailing copies of King Follet’s[sic] funeral sermon. At the time I was somewhat surprised, because I have thought that the report of that sermon might not be authentic and I have feared that it contained some things that might be contrary to the truth when I knew just what it was, so I did not reply to the letter. Not being very well, I did not feel like taking the matter up, and have learned since that some of the other brethren felt as I did and thought that greater publicity should not be given to that particular sermon.”

Full text here. Photos here and here.

Mormon apologist Blake Ostler writes,

“The First Presidency demonstrated its opposition to the idea of man’s necessary existence again in 1912 when it removed the King Follett discourse from [B.H.] Roberts’ Documentary History of the Church. Charles B. Penrose, in particular, doubted the authenticity and correctness of the reporting of the sermon.

Oh, what might have been 🙁