At 298 K on the QCT/PES-2023 results, the NMA analysis reported more than 300 populated HCN(v1,v2,v3) vibrational states, and 150 states with population > 0.1 %, the most populated state, HCN(1, 0, 1), presenting a population of only 8%. This picture is similar to those obtained in our previous work on the CN + CH4 reaction, and they clearly show that these low populations will represent a challenge in experiments. Figure presents the lowest bending vibrational states, which show practically Gaussian distributions of the bending mode (i). The population of the pure stretch and combination of stretching states and bendless excitation, HCN(v1, 0, v3) has been a debatable issue in the experimental literature. While Copeland et al. and Morris et al. reported initial state population (although no quantitative information was reported), Bethardy et al. found that they were not initially populated, or that at least the initial population in each of these levels was <1%. However, this result contrasts with that obtained by the same group a year later for the CN + CH4 reaction, in which about 20% of the HCN product was initially produced in the bendless HCN(v1, 0, v3) states which, a priori, is surprising because both reactions present similar dynamics. In the present theoretical study, we found a population of 22%, which agrees with Copeland et al.