This was from someone named Karen who is apparently a wedding coordinator. I have no idea who she is, but she used the email WDW.DCL.Ceremony@disney.com. I followed up asking if she was saying a paying customer couldn't photograph in public spaces on the ship. This was the response:
I followed up again asking what the specific rule or restriction about this was, who constituted a professional photographer and what rules they had around professional photographers who are paying guests and whether they are allowed to take pictures around the ship. No response yet.
Of course guests can take photos on the ship. However, a professional photographer taking photos of your group outside of your event area will be noticed by the staff. We want you and the photographer to be aware of this so any issues can be avoided and not disrupt your happy event.
I followed up again asking what the specific rule or restriction about this was, who constituted a professional photographer and what rules they had around professional photographers who are paying guests and whether they are allowed to take pictures around the ship. No response yet.