ccGenericServices

Should generic services be generated in each language? “Generic” services are not specific to any particular RPC system. They are generated by the main code generators in each language (without additional plugins). Generic services were the only kind of service generation supported by early versions of google.protobuf.

descriptor.pb.swift:1114
var ccGenericServices: Bool { get set }

Generic services are now considered deprecated in favor of using plugins that generate code specific to your particular RPC system. Therefore, these default to false. Old code which depends on generic services should explicitly set them to true.