As discussed somewhat in chapter 8 of Millenialism and the Anti-Polygamy Campaign, leaders made promises that arguably went unfulfilled. I’ve tracked down some regarding the building up of Jackson county:
Brigham Young, April 6, 1845 (Times and Seasons, vol 6 no. 12 pg 965):
for as the Lord lives we will build up Jackson county in this generation
Lorenzo Snow, as President of the Quorum of the 12 (Conference Report, April 10, 1898 pg 64 [pg 66 in pdf]):
We are not going tomorrow, nor next day, this week or next week; but we are going, and there are many—hundreds and hundreds within the sound of my voice that will live to go back to Jackson County and build a holy temple to the Lord our God.
Lorenzo Snow, as President of the Church (Conference Report, October 1900 pg 61 [pg 63 in pdf]):
Now the time is fast approaching when a large portion of the people that I am now addressing will go back to Jackson county. A great many people that are now dwelling in the State of Utah will have this privilege. Whether I, President Cannon, President Smith, or all the brethren of the Twelve will go back I know not. But a large portion of the Latter-day Saints that now dwell in these valleys will go back to Jackson county to build a holy city to the Lord, as was decreed by Jehovah and revealed through Joseph Smith.