The first two arc were about ghosts from the past and Zee will be dealing with her father.
I'm 90% sure Nightwing arc will revolve around Jason.
Neither Ra's or the league are to be trusted and the only reason the Batfamily didn't storm the league's base is because they don't know Jason is there cause league probably fucked with his brain, judging by the way he said Grayson's name last season.