Yes, I actually heard from a local modeling studio person that's their standard. I read about it's relation to 645 somewhere on photography related forum. It makes sense, doesn't it?
On my D2, on all format, 35mm, 645, 6x7, and 6x8, the hole on the neg carrier is ALWAYS little smaller than the frame size on the negative. It always crops a little. I find it strange that yours doesn't... I always account for this when I shoot. I also account for a need of 'waste space' around what I want to put on paper as to leave a clean borders around the images, I need to cut-off enough so that I don't get fuzzy borders.
Which all gets involved when OP tries to print full frame with no wasted neg space onto a paper. He really won't be able to do it unless he wants to print almost like dirty border type printing.