First, you read incorrectly. Nearly 100% of electrical wires in the United States are made of copper. Wiring made from copper is the industry STANDARD. Second, unless the insurance adjuster is an electrician, he is not qualified to determine whether or not this is any sort of hazard. Third, if the electricity to those rooms is turned off, there is NO hazard, since there is no electricity to the wires.
Yes, the rooms without electricity are an inconvenience. However, a simple extension cord or two will solve that issue until the damage is assessed and repairs are completed. There is no action for you to take, since there is no violation of code here. The affected rooms are disconnected, eliminating any electrical hazard. Be patient and wait for an electrician to appear.