Yes, because aspirin is a COX-1 inhibitor and a COX-2 inhibitor, this might well be expected.
However, 82.5 mg or even 325 mg of Aspirin has a short half life and will be gone in a few hours. This few hours allows one to take a reasonable dose of Niacin that might not otherwise be tolerated. which can clear out a lot of toxins which reduces the likelihood of severe flush with future doses.
Even if one needed to take aspirin for 3 or 4 days, it will not have that significant of a negative effect in the long run and the overall benefit of niacin is enhanced.