In Mockingjay, Katniss continues to be our narrator – for better or for worse. Since we're pretty much hearing Katniss's thoughts, we can see clearly what's going on in her mind. What we can't see clearly, though, is what's happening outside of Katniss's mind. This makes the story feel really personal, but we can't help but feel like we're missing out on some info.
Katniss sometimes drifts into depressive fogs and we have no clue what's going on in the wider world. For example, after she kills President Coin, and she's imprisoned in a room contemplating suicide for days – maybe even weeks or months – things are happening in Panem. Katniss trial is being held. A new government is taking shape. But since Katniss shows little interest in living, we don't get many details about the fallout from the war.
Was there any information you were hoping to learn about Panem, or characters besides Katniss, that you couldn't find out because Katniss is the narrator? If the story had been told by a third-person narrator, how would it be different?