Penguin makes sense. (Although I'm not sure if Ma Gunn knows about the confrontation with Penguin.)
I was thinking about something else. Theoretically, if Jason had read those letters as kid, he could have asked Batman for help later and they could at least have saved Willis from Hierve El Agua.
And as far as I recall, Jason doesn't know if Willis is alive or dead.
I don't mind little artistic inconsistencies like that. In most cases I think they are funny (for example Jason's shirt color is changing in RHatO #21 from blue to white and the woman in the casino - Emory - wears at first a red skirt with a red cropped/bra-like top. Later it's suddenly a dress).
Has Jason ever called Roy a brother before? As far as I can remember Roy was always depicted as Jason's best friend.