Not phonetically identical
Not phonetically identical; this is a Siri screw-up. The date (which should be 11/9, but US'ians do their date in the nonsensical order month/day/year instead of day/month/year) is pronounced "nine eleven." The emergency phone number is "nine one one."
Despite this, I'm sure there'll be a few of the conspiracy theorists who take this to mean that... umm... lets see... I guess they'll decide Apple and Siri are in league with the CIA (who really took the buildings down, don'tcha know?) to prevent people finding out the truth.