Old, but here's .02 fwiw:
If you have no role in an event, other than placing a call, don't bother clouding a 911 call with your arming stance. I have been on so many calls where the dispatcher sends you to the callers apt, rather than where the issue is.
Under stress, the dispatch area gets chaotic. People are multi-tasking and cops in the field may not hear the whole transmission (radio turned to low, people yelling in the radio, "clipping" the transmission, talking over someone, on another call).
If you want no involvement (don't want the neighbors to know who called), advise the PD NOT to come to your door, but to call you on the phone.