Egypt is worried about hundreds of thousands of Palestinians moving to Sinai - and their remaining there. That is why there is opposition to the expansion of the fighting to Rafah and taking over the Philadelphia axis.
The problem: Israel must act in the area and deal with the smuggling route of Hamas. The possibility of permanent Israeli residency in the Gaza Strip is slim, because it will be perceived in the world as a renewed occupation. Since Israel has already made it clear that at the end of the war it intends to completely disengage from Gaza, it will have a smooth passage for Palestinians.