This makes sense because information about controlled substance prescriptions are stored in a central registry so law enforcement or other government agents can review them easily. The federal regs only apply to controlled substances, so the e-script systems 'probably' direct controlled substance scrips to the DEA registry. But, the health providers, insurance companies, health systems, pharmacies networks/chains, and so on, are probably keeping a copy of everything.
I’d assumed that was for all prescriptions, but it could just be controlled substances.