How have some areas of controversy or uncertainty become clearer?

Can you tell me what contreversy you are referring to? 

Well, here are some things I think are controversial. The marriage of vladek and mala, how the poles treated Jews, and the relationship between art and vladek. And it doesn't have to be from book 1 to book 2, just any controversy or uncertainty that was cleared up by the end of the book

what are the uncertainities in maus 2