Religion and history intersect in fascinating ways and this article does well to point out the early movements of Hebrews, Philistines, and Egyptians.
I would add that the most important development at this time was the gradual transition to Hebrew monotheism (a belief in one God), which is even more important than the concept that the Jews were slaves in Egypt. Although deliverance from slavery is a vital motif, as were the wars with Philistines and other dominant neighbors, monotheism was a radical leap that took centuries to sort out, and it became truly revolutionary when it took hold.
The ancient world was polytheistic and virtually all of Israel's powerful neighbors were polytheistic. But the central story about the covenant between God and Abraham — and the continuation of this story with Moses and the prophets — makes it clear that what gives Jews a distinct identity is their relationship with a new type of transcendent deity. (A god outside of time who interacts with people over the long haul.) This concept and insight became revolutionary, and also hard to live up to. It is the core insight that would also form Christianity and Islam.
Did the Exodus happen? The biblical stories about the Exodus (estimated around 1250 BCE) contain elements that many secular scholars believe to be representative of real experience in Egypt. However, the stories are also mixed with other narrative elements and material that was reworked in later times (i.e. the Babylonian Captivity, where solidifying Hebrew identity was essential). If the Jews were not actually in Egypt, then they had some important information about what happened there, and they also found it important to internalize their experience of being delivered in freed — this is a major motif in the Hebrew Bible.
For my money, I think that the Passover is more than just a reflection on war with the Philistines — it is a core story about Jewish identity and a relationship with a new type of divine being. This insight would profoundly shape history, religion, and culture, even though the Hebrews were a relatively small Near Eastern power.
