So Facebook wants to non-ironically throw back to the early 2000s when every betch set her away status to an inside joke or angsty song lyric. They're calling it "side bar" (read: side eye) and you set a status, emoji, and location. They're only posted for 12 hours, and your friends see the away message on a different screen. Facebook's vision is that people will post things like "stuck in traffic" or "feeling excited." But they'll probably just turn out to be "living with my ladies #living" and "watching tv," so basically a way to figure out who's lying about their Friday night and who's boring as shit. The whole thing sounds like a stalking mechanism.
It's only available in Taiwan and Australia right now, and hopefully will stay there, because the best away message of 2015 is your Snapchat story.