Yes. I’ve read 1491 and have a certain skepticism about the extent of this. I don’t recall reading, for example, that the Inca Empire or the Aztecs were either already decimated or became decimated after contact. Not to say they did not have epidemics, some serious - but the concept that they killed off 90% of the population (rather than the Spaniards enslaving them to their purposes) seems to be a detail lacking in history. Plus many of the declined civilizations - mound builders of the Mississippi, the cliff dwellers of the southwest - appear to have failed due to climate change a century or two before the arrival of the Europeans.
Similarly, there is nothing mentioned in the records of the Iroquois nations, a widespread organized group, that they were horribly decimated at about the time the white man arrived. The horrid death of 90% of the people during a short time and the disruption implied would certainly be something memorable and mentioned over the next centuries by them. By the time the Europeans were taking over their lands in the 1700’s, they were a well established populous group with decent agricultural cut-and-burn spreads around each village, despite contact for almost 100 years.
More interesting was a discussion I saw about the smallpox epidemic along the northwest coast from Vancouver to Alaska in the late 1800’s. The records seem to indicate the problem was subsistence lifestyles. A small village would become infected all at once, with nobody able to provide food or water to the feverish - so almost all died, probably of ancillary causes like exposure and dehydration aggravated by smallpox fever. In villages where there was someone already immune - a previously exposed villager or a missionary - the death rate was a lot less, sometimes no worse than the 10% mortality rate in European outbreaks. It wasn’t the bad immune systems, it was lack of any immunity to specific diseases and so lack of support structures.
So… the truth lies somewhere in between.