Well, the article said it was sudden.

In addition, a person dies for a reason, regardless of the age. The older you are, the more likely there is "a reason," and the reason is always clinically determinable; cancer, pneumonia, car accident, shot in the head, vaccine injury, etc.

In this case, according to the article, the reason was "suddenly," which is not a clinical reason. Thus thinking it was suspicious (such as vaccine injury) is perfectly reasonable.