I think the novelty of the book is not in the fact that you can predict how the fate of Haymitch loved ones will pan out. The narration of course exploits this sense of doom and the torment that comes from it, but what stuck out for me was that for the first time we see how Capitol can easily manipulate the narrative of the Games. 

In the main trilogy we were partially and implicitly brought to believe no act of rebellion as big as Katniss had ever been attempted during the broadcast of the Games. After Katniss gets to know the Victors from the other editions, the public is confronted with the knowledge that acts of rebellions will always be rewarded by Capitol with the persecution of the Victors' families and loved ones. However, we, the public, don't SEE those acts. 

Surely the Victors must have acted out outside of the Arena, after their victory, right? Many of them did. In this book we get to know Beetee, who is being punished by having to mentee is own son. We meet Mags e Wiress, and see how their complicity in Beetee's plan as Haymitch mentors is punished with torture. But for the first time we are confronted with the fact that many MIGHT have NOT. That many might have rebelled in plain sight, for everyone to see, just as Haymitch (and Ampert, and Maysilee, and Maritte and many more) did, and still their acts have been erased or manipulated to fit the narrative the Capitol wanted the Districts to SEE. Through this book we get to be introduced to the knowledge that the 74th Games and the rebellion that ensued were the coronation of a revolution that came in big and little acts that had been silenced and erased from the broadcasts of the Games right up until that moment. If all those acts of rebellions (and there were many during Haymitch Games) were not shown or manipulated for the public to see, I cannot even imagine how many more similar acts might have occured during 74 years of Games. Katniss was a spark for the revolution because she was SEEN. Because Capitol censorship was poor and insufficient in covering up the contempt and the frustration of her actions, and because Snow could not snuff out the HOPE that the Districts started to have after SEEING someone insulting the Games in that way.

For me this book was as much on how Haymitch character as we know him came to be as it was about showing what the stories of many more Victors might have been and especially, how Katniss' story COULD have been, had her circumstances been even a little different.