The synic in me says that there's more money to be had in getting it into the Japan shops first and that the manufacturing/pressing of the discs will be aimed there first for that reason.
Knowing our luck, the UK release will only be in one outlet in London and require a Black Amex card or insane credit rating to purchase - just like the good seats at the O2!
However, the fact that date has been given I do fear is only because the big Xmas sellers in the UK are all released on that Monday before Xmas every year. What makes no sense is that there are so many DVD/Bluray titles that are up for pre-order after the Xmas season, but this sole title is missing even still.