I was thinking some more about this. Since your blocks are on point, I am wondering if the edges are bias.
Also wanted to mention that "quilting it out" refers to the fact that quilting can hide less-than-perfect piecing. It doesn't really refer to camouflaging excess fabric in the top.
One other thought is that quilting can actually shrink an area. If you have quilted heavily in the center, the edges may look as if they have excess fabric when actually they simply don't have the same amount of quilting yet to shrink them. It is often recommended that quilting be done evenly over a quilt, as having areas that are heavily quilted will actually be a different size than areas that are lightly quilted or not quilted at all. So, now I am wondering if you are perhaps just seeing the "shrinking" effect of quilting the middle area; perhaps all will be well when you have quilted the outer edges to the same degree as the middle.