If they were going to do that, they would have built the house over the brick facing. I've seen it done in a crawlspace but the bigger blocks were put with the extra width of the block inside the structure. I think the mason was using up some extra block, in this case, it wasn't needed structurally.
I would fill in the holes with concrete or possibly mortar and slope it away from the foundation. Then since you have space above the ground add dirt to slope the yard away from the foundation. I'd fill it in to keep ground water out of the wall. If you have a basement, filling the webbing up with water is a sure-fire way to get water into your basement. If you have a crawlspace and are in an area subject to freezing water could collect in the block and freeze.