The text is infinitely varied and just as expandable. Like history itself. As if each generation were part of some great procession with a purpose, still following a pillar of cloud by day, a pillar of fire by night. Both, of course. Each generation is to celebrate this watch-night as if it were the one leaving Egypt in haste.
All slavery is alike.
But there are different kinds of freedom. There is a freedom that comes after freedom, as the Children of Israel were to discover in the wilderness. No promised land awaited, only the hazards of the journey. Freedom is hazard. Yes, there is a kind of brief, hollow freedom that is only the absence of slavery.