Regardless of the exact dates, it's at the least poor planning, and borderline inconsiderate for Disney to close an attraction at the exact same time three years in a row. Some people may only have that one window of opprortunity every year to travel to Disney. Doesn't seem right to do that. I can understand avoiding peak seasons, but there are other windows throughout the year where things like this could be done.
And, as someone mentioned above, what is so wrong with the railroad that it has to not only be closed, but be closed for weeks at a time for three straight years?