The timing of the clear fulfillment of the prophecies emboldens the unbelievers. They take courage from the fact that it has not happened yet, and that the time period is arguably over. They continue to put pressure on the believers.
For the believers’ part, they attempt to continue in faith, but the faith is not as firm as it was when there was the clear prophecy to await. In the wake of the possibility of failed prophecy, they “began to be very sorrowful.” Of course the event will come, and come soon, but their faith was tested, nevertheless. They would have done well to have heard Moroni’s caution:
Ether 12:6
“And now, I, Moroni, would speak somewhat concerning these things; I would show unto the world that faith is things which are hoped for and not seen; wherefore, dispute not because ye see not, for ye receive no witness until after the trial of your faith.”
The perceived delay in the fulfillment of the prophecy was the test of the believer’s faith. Perhaps the timing of the fulfillment and the prophecy was designed to be this trial of faith. The trial would escalate rapidly.