This is the last effort at getting civilians out of the way, before the final push.  As ISIL has no conscience reflective of humanity, there is the vulnerability of suicide bombers, and war criminals wanting to join the exodus.  They would be around the children armed to protect them.  Make no mistake, there have been plenty of pauses to get the NCs out.  This pause should not be more than 24 hours in length.  And then it is back to wiping ISIL from the body proper of Earth.