If this is the distant past, how was Christian there at all?
Let's say for the sake of argument that the scene takes place just before the Black Rock crashes into the statue of Taweret back in 1867. The Man in Black would exist then on the island, but this 1867MiB wouldn't know who Locke is. He also wouldn't know about Christian Shephard or about his future 2004MiB self.
The only way I can think of to explain how 2004MiB is in the frozen wheel chamber prior to 1867 is that he was time traveling during the time shifts as well as the others. This would explain how he is able to still impersonate Christian (who hadn't even been born yet), plus how he knows what his 2004MiB self had planned and accomplished. He knows all this because he IS the 2004MiB.
If this is the case, the implications are staggering, as far as MiB being able to travel through time and acquire all kinds of info. Perhaps 2004MiB even met with a past version of himself, telling himself everything he knows about the future.