Answer to original question...
...Because "No Flightwatch" is not correct.
Only Flightwatch provided on discrete frequencies is not available....and to help in understanding that, the discrete FW freqs and the areas they cover are listed.
The opening sentence sums it up pretty well...
"ON-REQUEST FLIGHT INFORMATION (FIS), SARTIME AND EMERGENCY
ALERTING SERVICES NORMALLY PROVIDED BY FLIGHTWATCH ON DISCRETE VHF FREQUENCIES ARE NOT AVBL"
**All** flightwatch services **are** available on ATC FIA frequencies and
HF as indicated by the closing words...
"ON-REQUEST FLIGHT INFORMATION (FIS), SARTIME AND EMERG ALERTING
SERVICES AVAILABLE ON ATC FIA FREQUENCIES OR HF (REFER ERSA FAC-B BRISBANE ACC/FIC AND FAC-M MELBOURNE ACC/FIC)"