If you follow the link you'll see the procedure is you call the non-emergency number to ask for a time and location slot where you're allowed to call the real 9

If you follow the link you'll see the procedure is you call the non-emergency number to ask for a time and location slot where you're allowed to call the real 911 number for test purposes. This let's them schedule you for a time where they predict lower demand. Seems sensible to me.