I have had this same thought on numerous occasions, especially if government "kills" the Internet via draconian control of its traffic. Youth returning in great numbers will drive the idiots away and they'll use the Class D service for a number oof things it wasn't originally intended for - such as digital trasnmissions.
A linked data communications system which utilizes HF (CB), VHF (MURS) and UHF (GMRS/FRS) along with 802.x technology is not only well within the realm of possibility but is in all likelihood inevitable.