Christmas isn't a particularly religious holiday regardless. The holiday has become a secular event with peculiar traditions that rarely reflect any religion or denomination of a religion. The holiday is basically worship at the alter of consumerism. A excuse for consumers to buy goods for family and acquaintances that feels more like an obligation.
Looking at last years sales charts the holiday seems to have no meaningful effect upon game sales within Japan. So I wouldn't consider the timing to be poor. Were it in the West it would most assuredly be horrible timing. With the majority of retailers being closed for the holiday.







