It seem CN Tumblr teasing Fifth StevenBomb will answer the show's secrets http://cartoonnetwork.tumblr.com/post/154765550284/this-january-stevens-universe-gets-a-little
We don't know which secret that will be Answer but giving the picture of Pink Diamond's Palanquin. I going to assumed it will answer about Pink Diamond and possibly Homeworld
The Zoo is very interesting one as this episode is before That Will Be All which is basically Steven and Gems are trying to escape from whom! I think The Zoo will actually being part of Homeworld...... Oh dear, I just realized that we finally get to look at Homeworld Planet for first time! OH MY GOD! We are going to see HOMEWORLD PLANET! THIS IS NUT!