How does providing a router put SSNs and health information at risk? Is the county transmitting that information without TLS? Then it's already at risk.
I imagine Maricopa county has no interest in throwing away all these routers and buying new ones. This is on top of the disruption of service that providing the physical routers will cause.
The whole letter is worth a read by the way:
https://www.maricopa.gov/DocumentCenter/View/70435/Final-Sig...