What does Katniss learn from Haymitch about the situation in District 12?

Haymitch lets Katniss know that he does not believe that rebellion with work in District 12.

Haymitch and I can speak in a kind of shorthand now. In a few minutes I've updated him and he's told me about rumors of uprisings in Districts 7 and 11 as well. If my hunches are right, this would mean almost half the districts have at least attempted to rebel.

“Do you still think it won't work here?” I ask.

“Not yet. Those other districts, they're much larger. Even if half the people cower in their homes, the rebels stand a chance. Here in Twelve, it's got to be all of us or nothing,” he says.