Much of the message of the Theban plays by Sophocles, and especially "Oedipus Rex" is that fate is not avoidable. If you consider the story, Laius tries to avoid fullfilling the prophesy of being killed by his son by exposing Oedipus on a hillside. Oedipus tries to avoid fullfilling the prophesy of killing his father and marrying his mother by leaving Corinth. In both cases, the actions taken to avoid the prophesy are what cause the prophesy to be fullfilled.
In the case of Oedipus' character, if the gods have perfect foreknowledge, and prophesy reflects that, then the gods would be able to discern that Oedipus' character is such that will cause him to act in a certain way in the future.
Another thing to note is that "hubris" does not mean "pride" in ancient Greek, but means something closer to "aggravated assault." This misreading of Aristotle is a common misperception due to the fact that pride is what leads to hubris.