As a joke: “The heroes must finish their project by Monday”
Another joke: “Jockington’s glorious beard must be shaved”
I have also seen similar things about death, like “In the end, the dragon must be slain, “the prince or the girl must break the cage,” and at least a few along the lines of “the grand fountain must be sealed away.” I think I saw one about memories or the timeline as well, probably for the theory that the prophecy is a cycle, but i don’t remember what the wording was.