I think so, because
1. The epidemic began in the middle of the Basin of Mexico, which was also the Aztec heartland, and killed a third of the population of the Basin. The Aztec capital of Tenochtitlan was also heavily struck by the epidemic. While it is true that Spanish allies (importantly the Tlaxcalans) were also struck by the epidemic, the epidemic began in the Aztec heartland and consequently it killed more people in the Aztec heartland than in, say, Tlaxcalan territory.
2. The disease also killed Cuitláhuac, the tlatoani of Tenochtitlan (the tlatoani of Tenochtitlan being what we often refer to as the Emperor of the Aztec Empire). The death of Cuitláhuac meant that in just two years, there were three tlatoanis. This led to even more political chaos in the empire, especially because many of the most important Aztec nobles were killed during the Massacre in the Main Temple only a few months before. Cuitláhuac, having led the Noche Triste, was also a capable military commander.
3. The epidemic killed many leaders of Spanish allies, which enabled Cortes and the Spaniards to make sure their successors were friendly towards the conquistadors.
Thoughts?