It's far, far, far too obvious that "the fall of the 11th" means "the 11th Doctor". I'm certain it's a red herring. More like, "the fall of the 11th Legion" or something.
Which makes it likely to happen. Every single time that I've talked with my friends I've said "plot point x is too obvious/lame for Moffat to use," and ever single time he's done it.