I get this question all the time, in fact I got it last night and again this morning. The short answer is “No.” It really isn’t important for your photographer to have shot at the location before. Any skilled photographer is going to be able to shoot at any location. Period.
I shoot destination weddings all the time and don’t get to see the location. I arrive and start shooting. Photographers look for light and that is where they will gravitate. Next they look for background or textures. On any given property there will only be a handful of locations truly worth shooting and they will be instantly apparent to most photographers the second they see them.
So why do you hear that it is so important? Many photographers are on a vendor list, one of a recommended few from the venue who have worked the property before. Venues like to work with people they have worked with before because it makes it easier on everyone. It doesn’t mean they are the best choice of shooter, it may just mean that they are the easiest to work with or that they have a long standing relationship.
Photographers like shooting at good venues close to their house and so make a point of letting you know that they are the right person for the job since they know the property so well and have shot there before. In reality, it’s just not that important. In addition, having shot a location too many times makes them complacent and not really look for new ways to carve amazing images out of a location so it could even wind up being detrimental.
The Real 411: Pick the photographer whose composition, lighting, technical skill, post production and personality you like, the rest is conjecture.