Board Thread:Misc./@comment-28958062-20170825191100/@comment-1327106-20180107013948

Considering that scene is from the anime when Reiner and Bertholdt get revealed as the Armored and Colossal Titans (that's Reiner jumping down from Wall Rose), I doubt that's Annie's crystal. I saw the flash and it definitely looks odd, but I don't think that it could be Annie since he was just holding Eren in the same hand a moment ago.

There is supposed to be some original story material for the game, supervised by Isayama. Since RBA are now playable with Titan forms, I wouldn't be surprised if there aren't some game-only missions centered around them since it seems a waste to add them and then not give them something cool to do with all the new Titan forms the dev team has no doubt been laboring hard over. But this is just speculation.

What I think would be nice, is if they adapted RBA's original journey to the Walls as unlockable levels. While that hasn't been shown in the anime yet, it's been done in the manga, and the previous game has pulled yet-to-be-animated manga material when it was not a major plot spoiler. We know RBA came from the outside and made it to the Walls, so it should be possible to play that sequence without ruining much.