lib/cyw43-driver/src/cyw43.h line 94 says \see status_name() to get a user readable name of the status for debug, which I presume is the source of the same phrase in the SDK documentation (e.g. PDF section 4.4.4.7.9, page 446). There is no such API anywhere in the SDK, but a quick search shows src/rp2_common/pico_cyw43_arch/cyw43_arch.c:67:static const char* cyw43_tcpip_link_status_name(int status) that appears to provide the implied functionality.