I think it's about leaving their resources behind, like weapons, plans, and bombs. The tunnels are already collapsed due to the deep bombing, so if hamas wants to move anything, it will have to be done so in plain sight.

Yes.

Hamas, which controls the strip, told residents to stay put, and vowed to fight to the last drop of blood. By Friday afternoon there was no sign of any mass exodus as Israel prepared its onslaught.