I think Israel is just hoping they'll mass flee to Egypt, this way they get everything they want, no more Palestinian in Gaza without having to genocide them. They'll probably just turn most of the city to rubble over the next week, not to inflict mass casualty but just to force people to leave.Depends on what the Israeli response in the next few weeks are. Hamas is betting, rightfully so I'm guessing, that Israel is going full blood for the blood God, skulls for the skull throne crazy with their counter attack.
A thousand Israelis are dead, and the world is aghast. And then Israel turns around and kills....40, 50, 80,000 people in response. That's a huge victory for Hamas. Gaza is one of the highest density cities in the world, any ground invasion or air bombardment is going to have thousands of civilians dead with each strike, and Hamas is there with their phones ready to say "See the true face of the Jewish people!"
Remember Hamas wants to turn the world against Israel, and the actual leaders of Hamas are in Iran. They don't give a shit about Palestinian children. Or better yet, those children are more useful dead and on social media.
I really don't think the world will care much about the number of Palestinian death if at the end they can finally put that conflict behind and move on and Hamas just gave Israel the perfect excuse to finally get on with it.