While the "normal wheels" of government keep turning as systems and processes continue to function, the prioritization of work and focus for the department and its major elements will wane quickly. In situations like this, everyone seems to "shift into neutral" and getting decisions becomes impossible, since no one is sure which direction to head.
Children and employees like consistency. It provides for continuity in operations and keeps things running smoothly. While routine things will get done, there won't be real progress in many areas as people wait around for the next leader to appear. And, someone "acting" in a capacity is not the same as the formal designee.