Lets say how Hamas will proceed now. Will they remain in these areas or will they retreat back?
Remaining there, inside enemy territory and away from their home base will make it easier for Israeli forces to combat them. On the other hand, having controlled urban areas, Israel will suffer lots of casualties in order to drive them out.
I personally think withdrawing a big part of their forces while leaving a small part of them behind to booby-trap all these settlements and make Israel suffer, is militarily their best course of action to preserve their well trained and valuable manpower
Retreat would be the worst thing Hamas can do, as they have nothing to counter Israeli air power. Pull back and the Israelis can bomb them from the air with impunity and safety all the way back to the Stone Age.
This is a once-a-century chance for them, having somehow managed to catch the IDF out cold, they are now through the Israelis main defences and in their urban settlements, which massively limits the IAF.
This isn’t a war, the Palestinians cannot win this, it’s all about doing as much damage and causing as much pain as possible to the Israelis before they are defeated and killed.
I think the Palestinians knows this deal, and went in with clear eyes about the final outcome. This is why they won’t behave like a conventional military and try to hold ground and consolidate their gains. I don’t think they will even try to take back any of the heavy armour they have captured and will just torch them all on the spot, or drive them forwards to help push deeper into Israel.