As I'm sure people have pointed out, this was not even close to a 10x bump...factoring in holiday trends, the bump is at most 10K, if that. Apparently this expansion can only be played if you already own the game and because the original didn't chart this week, it was probably mostly bought by people who already owned the game (and therefore, the system). This implies that the bump coming this week was largely coincidental.
Also, learn some context. This is the holiday season, even in Japan...while the effect isn't as large there, constant HW bumps until the end of the year are pretty much expected for all consoles.