If any of you actually watched the trailer closely, you could easily draw the conclusion. If you watch the trailer again at 0.25x speed when they start fighting, a long red sleeve comes out her gauntlet as she swipes down on him. Also you'll notice a "Golden" line as well which would be the hidden blade. In FF Tactics Dancers used "Cloth" as a weapon or dagger in other instances, this incorporates both. Some people say "Oh but she's using Monk moves", Dancer is a subclass from Monk, duh. Others speculate "Red Mage" being released because Yoshida said something about Scarlet Witch. Obviously it's not a coincidence that the chakra of said dancer is "Red". Yoshida could be playing mind games.
If Yoshi's shirt was talking about dancer and not red mage there would be soooo many pissed people but also would be really funny. lol I like that idea just for that! lol