from the "that's okay, I didn't actually need my feels" category
So Haymitch tells us that in The Hunger Games the Careers win it nearly every year. Let's be generous and say they win it two-thirds of the time, meaning fifty victors from those districts over seventy-five years. There are, what, four or five of those killed off in the Quarter Quell.
In the Victors' Council at the end of Mockingjay there's a grand total of one surviving.
I am in no way imagining summary executions or organized assassinations as the Rebels gain power, by one side or the other. Ouch.