Global Warming, Invasion, Impunity, and yes Inequality
Also, trajectory of celestial bodies can be predicted with a somewhat decent level of accuracy. Pretending societal changes can be equally predicted is borderline bad faith.
Besides, you do realize that the film is a satire, and that the comet was an analogy, right? It draws parallels with real-world science denialism around climate change, COVID-19, etc. Dismissing the opinion of an "AI" domain expert based on fairly flawed reasoning is an obvious extension of this analogy.
I think "safety research" has a tendency to attract doomers. So when one of them quits while preaching doom, they are behaving par for the course. There's little new information in someone doing something that fits their type.