This is a question I hear a lot and while it's certainly a valid question and one that all the magazines tell you to ask the photographer is it really important?
Let's start by determining how experienced your photographer is in general, how many weddings have they shot? How long have they been doing photography? Does their portfolio show a range of situations, indoor and out, in daylight and night time?
These are the important issues you should be with concerned with.
The problem with someone who shoots the same venue again and again is boredom. Unless the photographer is very super creative (which you can determine from their portfolio) it could end up that they just churn out the same images again and again for each wedding, same spot, same lighting same pose.. Yawn....
Personally I so much prefer a new venue or one I have only shot at a couple of times, gets my creativity flowing, and I'm not alone in this. The general consensus from my fellow professional wedding photographers is the same..
I plan ahead, scout the place out, use google satellite images to see an overhead view, I use a sun position app to work out where and when sunset will be. Find out backups in case of bad weather and talk to the wedding coordinator to get the low down on the place.
I'd actually be a bit concerned if the photographer had mainly only shot at that one place. There are literally hundreds of venues these days and I'm always coming across a new one..
So is it important? If you do your research and hire a professional then no, not at all. More important is your relationship with photographer, how well you warm to them as a person and you like their style and ethos.
Its your day, don't be dictated to by out of touch wedding magazines.