Hawaii has been unique since the beginning of EBS.
The State of Hawaii EOC acted as the local Primary Entry Point. All the other PEP stations on the mainland are commercial broadcast stations, based on early EBS working agreements between NAB, White House, FCC and predecessor agencies of FEMA.
AM-radio station KHKA, CBS 1500 is now designated as one of the FEMA "PEP" (now called NPWS) stations. Another article says KHKA would also acts as a terresterial backup PEP relay for Guam and American Samoa. I don't know my AM propagation effects over oceans, how effective that would be.
CONELRAD's original purpose was preventing long-range targetting based on AM tower transmissions, so that would be almost full-circle.