Its the norm. And its a good thing, and I'm not saying that from a professional wedding photographers view but from the view of the couple the vicar / priest and the fact that it is a legal / religious ceremony.
As a pro photographer you learn in weddings to be descreet, turn the flash off if required, and turn the camera to silent and just take photos when necessary.
What you don't want is dozens of guests taking photos flashing and bleeping away, becuase it is just so easy with modern cameras / phones.
Its actually really annoying and distracting.
Paul.
www.photographybyriddell.co.uk