We need to have a day where we all yell and scream profanities at diseases. We should stomp our feet as well, but not in any culturally appropriating way.
You are almost certainly correct. However, the number killed by disease was probably less than many make it out to be. The pilgrims were 125 years after Columbus introduced Asiatic and European diseases into the new world.
If the diseases spread with any efficacy, populations would have developed immunity and recovered in a couple of generations.
What we see is diseases causing large losses for 300 years, as more and more populations were exposed.
Eskimos on the North West coast of Alaska had large losses from disease into the 1900s.
For that matter, Americans and Europeans lost millions to the flu in 1918.
Old World diseases wiped out 90% of the New World people. The interesting question is why New World diseases did not do likewise to the Old World.