If Amon is going to attack during the pro bending finals, and this episode is about our heros reaching the pro bending finals. It could have ended with Amon and the Equalist getting ready for their invasion.
This is a breather episode, but I know a lot of animes even in breather episodes they sneak in some plot normally at the very end, after 20 minutes of fluff, last minute a cliffhanger. The original Fullmetal Alchemist anime had a breather episode which was about Havoc dating Armstrong sister and Mustang's crew looking for ghost, but it snunk in some plot. The Code Geass academy episode, which was always silly comic relief but ended with edge of your seat cliffhangers. I would have ended with Amon and the Equalist getting ready for the pro bending finals, Amon doesn't even have to talk, have one of his underlings talks and say "we are ready Lord Amon."