Allielyn's right. (Imagine that, the current and former Lead GMs having the same opinion...)
That said, if this is something you really, really want, your best course of action would be a Suggestions and Requests thread about turning that "raid of 13 or more" requirement down to "raid of 12 or more".
I don't know the reasoning behind making it 13+ characters in the raid, but it might involve how it would affect 12-man content (like The Abyss), so that would need to be addressed.
To the original question by JeffroCakes, though, the answer is "sorry, no".