People have been worried about pandemics since the first time a unknown disease hit a village in the stone age. The fact that Bill Gates chose to spend lots of money money on disease research does not mean he wants to cause a outbreak.
You aren’t connecting enough dots. I suggest doing more research on the other stuff he’s “into” like massively reducing world population and his and his family’s deep links into planned parenthood, as well as his beliefs about God.
When you get a bigger picture of what makes him tick and what he’s for, when you get more context you see what he’s about.
I remember watching, IIRC sometime in the late 90s, an excellent documentary about the 1918 Spanish Influenza, a disease that is estimated to have killed more people worldwide in a single year than in four-years of the Black Death Bubonic Plague from 1347 to 1351.
The conclusion of many of the epidemiologists and virologists interviewed was not if something like the Spanish Flu (a highly transmittable and lethal respiratory illness such as influenza or something similar) could happen again, but when it would happen again how prepared would we be, how air travel would spread it more rapidly and how medical advances since 1918 might make the difference (or not). Bill Gates is merely repeating the warnings that have been made for many years.