Board Thread:Questions and Answers/@comment-5270921-20131029040244/@comment-61022-20131117182112

It would seem so, there are many alternate versions of Earth-811. However, although I would not conclusively say that it isn't. Even though Days of Future Past happened in Uncanny X-Men #141-142 with characters that were in that era, the Days of Future Past universe has been visited multiple times in later stories. Namely the Days of Future Present which happened in the X-Men related and Fantastic Four Annuals from 1990. The "future" events in that reality also happened on Earth-811, and introduced then current members of the New Mutants to the Earth-811 universe. Also and  also featured the Earth-811 universe and introduced more characters who were then current into the Earth-811 universe (mostly Marvel UK characters like Killpower)

So is it definitively an alternate version of Earth-811? I'd say yes based on the principle that what *caused* that future (Nimrod killing Hope) until Marvel categorizes it otherwise.