Surprisingly... that movie was the best adaptation of a fantasy novel ever. It also was not historically accurate in any form!
In the fantasy novel called the Torah aka The Old Testament, it hit everything spot on.
Historically though, Ancient Egypt had never had Jewish slaves in its existence, and Jews owned well over 3/4 of all of Egypt's slaves during the 200+ years they existed at Ancient Egypt. Uniquely, a Civil War occured because Jews did not tolerate that they as foreigners where denied any and all means of ruling authority, which was only allowed towards native born folk who acted as clergy of their religion. This Civil War happened at a time when a commonplace series of events that happen every year for the past 100 million years that continue to occur in modern Egypt to this day befell the country, which included the annual Locust Swarms, the annual end of hibernation of frogs, the centinial occurence of red algae, and more.
Many people love to party, the ancient Egyptians partied over peace and properity, the Jews partied over the successful conquest of inferior lifeforms and the gathering of them as slaves. If anything, everyone deserves to party.

I don't read much into the bible these days, but I remembered this movie and how moving this song was and how the scene used to scare the shit out of me as a kid, haha. Also I did not know any of that, thanks for the little history lesson! :) And yes everyone deserves to party hard!