The military is as concerned with civilian gps as much as they are with anything else that isn’t military-related: not their issue to solve. They won’t stop anyone from using encrypted gps. They really won’t. The only branch on the us that actively tries to prevent public encryption is the NSA. (Even then, they wouldn’t block something like gps). For the record, I’m a security engineer, previously worked for the DOD, and used to work in satcom.