Notify NYC Announces Tomorrow's Annunciation

As a New Yorker who was here on 9/11 I was an early adopter of the City's Notify NYC alert system.  As the City explains on its sign up page:

Notify NYC is the City of New York’s official source for information about emergency events and important City services. What you need to know, when you need to know it.

Obviously a good idea.

Since signing up many years ago I've received dozens of messages from Notify NYC.  (You can have them sent as text messages to your mobile phone as well as email messages to your smartphone or PC.)  And they cover everything from a mundane June 23, 2008 advisory like this ...

Due to a traffic accident at Bowery and Canal Street, there may be traffic impacts throughout the area. Avoid the area if possible.

Emergency personnel are on scene.

to this September 6, 2008 alert ...

The National Weather Service has issued a TROPICAL STORM WARNING for The New York City area in association with tropical storm Hanna. Additional information to follow.

to the nutty message I got earlier today ...

Notification issued 12/6/11 at 12:00 PM. The Port Authority of New York and New Jersey will be conducting a test of the World Trade Center Site Annunciation System tomorrow, December 7, 2011 between 7:00 AM and 10:00 AM. There will be no evacuations or impact to the public associated with this test.

When I read this email I tripped over the word Annunciation and thought: Doesn't that have something to do with Christ?  (Confession: No, I'm not Catholic.)  That can't be the right word for this system, can it?

I had to look up the word to make sure I wasn't losing my mind.  Here's how Dictionary.com defines it:

OK: so definition #4 sorta applies as a name for what should probably be labeled (if it didn't sound a little too Cold War scary) an early-warning system.  But if proclamation works as a synonym for Annunciation, it still seems to me this isn't the best word to use.  What's wrong with calling it an Announcement System instead?

Announcement is such an obvious choice I'm left wondering what the motivation could have been for substituting the religiously loaded Annunciation.

If you think you know, please leave a comment and enlighten me.