Fullness of the Gospel again…oh brother

D&C 76:14; “Of whom we bear record; and the record which we bear is the fulness of the gospel of Jesus Christ, who is the Son, whom we saw and with whom we conversed in the heavenly vision.”

D&C 19:31; “And of tenets thou shalt not talk, but thou shalt declare repentance and faith on the Savior, and remission of sins by baptism, and by fire, yea, even the Holy Ghost.”

Vision given in Hiram, OH on February 16, 1832.  History of the Church 1:245-252. 

This can’t be true because it contradicts a previous revelation to the missionary Saints.  (D&C 19:31; “And of tenets thou shalt not talk…) 

Are they to bear record of what they believe or not?