The title of an episode is something the creators can change at the last second before releasing the final date. Do you guys really think that thye don't read the ATLA forums as well? Ofcourse they do... I'm 100% sure they even responded to certain mass requests, since they say that they ARE listening to the fans and viewers.
Thats being said, I think they might want to surprise us with anything that might change or happen in the finale, including the title. So I guess they would just pick a title which no one expects
Ofcourse this is pure speculation, but the creators even wanted to surprise the Track Team (music/sounds team) with the finale since they waited for the very last moment telling them their final plans for the last episodes.