There are many techniques recommended for handling prophecy (precognition, etc.) in RPGs. You have the option to stick to one of them or combine them.
The prophecy describes what would become of things if no one knew it. In other words, the very act of looking at the future is likely to change it. Of course, some events may or may not be easily changeable. It is quite possible that an aversion to a prophecy be subordinated to a series of very difficult actions that were triggered by the discovery of the prophecy and whose success or failure is still in mutation.
Something is predicted (usually verbally, sometimes poetically), and predictions are carved in stone. however, what exactly does the prediction mean is ambiguous enough that it can be done in many ways. For example. "You will conquer all the observable universe one day before you die" could mean either conquering everything or being locked in a tiny pocket size; or it could mean that the world will be so desperate to defeat you that other powers will spread a small part of the universe and eject it into a pocket dimension (as the Orions did with the Antarans in Master of Orion). There is a lot of space for variation.
Beware: Direct words can be disappointing and give the impression of being "trapped" if players do not like word games. It can also lead to reduced activity by reducing the ability to informed choice (an uninformed choice can often be as bad as no coin1).
But if your players are on board with such a style, go for it.
The facts presented (and they are usually shown, not described) are carved in stone, but there is very little information about what surrounds them, which makes them maybe not so bad, or not so good, or whatever. I have seen a similar principle proposed to solve certain paradoxes of time travel (for example in GURPS infinite worlds).
This kind of twist is Probably more satisfying for players who like to have a more direct and direct influence on what's going to happen, and feel less comfortable.
The prophecy will come true as planned. However, knowing that this will always give the PCs an opportunity to prepare for and mitigate the consequences. For example. you know the impact of the asteroid and that it can not be avoided, but at least you can now start building an ark.
Prophecy sets in motion events that make it possible. This variant can be either engraved in stone, or the prophecy can be on a potential future. Usually, it works best with positive prophecies (eg, "You are destined for greatness, Po!").
Keep in mind that these operations are often tricky to configure if they depend on the actions of the PC, and may result in an urgent need for a railway if they do not work in the beginning.
A parameter may have only one of the above types of prophecy, or combine them freely. There may be several types of prophets, or perhaps each school of prophecy can only access the prophecies of one of these types.
1 Related: for the same reason, imprecision (verbal, symbolic-visual or visual insufficiently informative but concrete) can render a prophecy useless: you can not use your knowledge of the future if you do not have real knowledge, just a string of words.
Sarah Connor Chronicles Sarah is convinced that a triangular pattern (three points, three lights, etc., in a loosely triangular pattern, which corresponds to most configurations in which three points can be), has a deep meaning, and begins to seek deep meanings in all that corresponds to the model. This is largely a wild goose hunt and she begins to doubt her ability to find meaning in this hunt. This is what players will probably feel if they are presented with a model that can apply to anything or anything. (In addition, it is notorious that humans observe patterns where they do not exist, which leads to many false positives in all the wrong places.)