I think the author is either deliberately downplaying Heller or doesn't have a good grasp of where Heller is on the continuum of Supreme Courts civil rights litigation. There was a long, long way between Brown v. Board of Education and actual equal opportunity. If we were to look at only the first year, we might well think Brown was insubstantial.
From my read of the abstract, while the author hits Scalia for lack of originalism, he correctly understands that the opinion itself is a work of compromise and that the non-originalism parts were designed to preserve many of the current federal laws and get those five votes. The whole point of the non-originalism is to flush the loser cases like the ones the author is counting in his survey. It was also probably necessary in order to get five votes.
I think over time, this decision is going to have much more impact than Professor Levinson gives it credit for. It really is a great blend of originalist interpretation of the Constitution combined with the practical necessity of getting votes/having the decision enforced by the other two branches.