Is it a big deal? Not really, but I am sure it will probably throw a few people off at first in regards to aiming their guns and explosives. I mean that is if there are no movement mechanics that will change based on this I am sure it will function like every other FPS out there, it will just look a little wrong at first. But imagine if they did? All of you righties out there would have to learn a little on how the other half live. We ambidextrous should move along with ease and those lefties will get something akin to left handed scissors in a right handed world.
Before you start flaming or trolling, as if, this is all fun speculation and playing around in regards to the screen captures we have here. Also based on my observations and need to put some text here to go along with the images. So take that as you will. Hopefully I just made you think back to every other game out there were the characters are always right handed as well.