We did find out who Lin's father was ^^;

It worked well given the little time they could store it in. I liked their curt greetings of each other ("Hey, chief."), and I'm glad we got to see understandable tension between them. Yes, I'd like to see more, but with 13 30-minute episodes this season, it's actually hard to ask for especially when it's... not exactly important to the story itself. It was about getting Suyin and her family back (I wish we got a nicer reunion between Suyin and Toph rather than a hug, but I'm guessing Suyin had actually seen her a while longer in comparison to Lin).