The keys that you can pass to status() are both port-dependent and mode-dependent.
e.g. ESP8266 supports "rssi" only (and only in STA). ESP32 supports "stations" in AP mode, and "rssi" in STA mode.
Ref: ports/esp8266/modnetwork.c and ports/esp32/modnetwork.c
So I'm guessing you're on ESP8266? Not sure if there's a technical reason for why "stations" isn't supported there, sorry.