Regarding the hostages, Hamas wasn’t gaining anything by keeping them, the best they could hope for was a prisoner swap, since Israel was more then happy to continue the genocide even if that would cost the lives of hostages. So releasing them will not cost Hamas any leverage, really.
But regrettably we don‘t live in a just world, and the best we can hope for is that this ceasefire will last long enough for the international community to step up their game and actually assert pressure on Israel to not only not break the ceasefire, but also to implement their obligations to international law and give Palestinians a) civil rights b) a political means of resistance, and c) self determination.