I kinda doubt that. First we dont even know if those Light Forces are sent from her, it could just be something that already existed (and seemingly the second lore book seems to hint that the ones in the dungeon are built in memories of such creatures?) that can now pass into our world (if its even our world and not a shard). That does not mean that it was done by Hydaelyn. She barely could talk to us and was only able to help in the other shard by using Minfilia. So she really had to lie a lot to us and at least until now nothing she has done was bad. She has shown fear for us, her children and lets not forget that the song Answers seems to be from her perspective too which hints again at a good god.
I am not saying that things cant change or that there are some moral aspects on her that could turn bad but that would come quite out of the left.
Who knows maybe the little girl in the trailer who is also seen being protected by our character in the art will be her? Maybe she wants to protect this world at all costs thus choses a human appearance for the first time?
