I'll be honest, this isn't really my area - I'm more of a Bigfoot bloke than a political conspiracy type. But I've seen this pattern mentioned a fair bit and I do think the sheer number of cases that fit this description is worth looking at seriously rather than dismissing.
That said I'd be cautious about assuming every single one is suspicious. Some genuinely will be coincidence or actual mental health situations. The problem is when you have multiple cases around the same investigation or the same circle of people, that's when the statistics start looking a bit odd.
Has anyone actually done a proper data comparison - like, do people in high-profile legal cases have statistically higher rates of sudden death before testimony compared to the general population? That would be the kind of hard evidence worth building an argument around rather than just listing cases. Anyone know if thats been studied formally?