The santa boxes still drop. But it seems like the santa box's probability of dropping goes down as rare drop probability goes up. This seems like true for elites and pets also. Let me give you an example: With x1: You have 40,000 marbles. 1 marble is purple, but the 39,999 are yellow. With x6: You have 239,995 marbles. 1 marble is purple, but the 239,994 are yellow. You have a lower probability of dropping non-Rare items but a ton of Rare and Unique gears. That 1 purple marble seem to be a mix of pets, elites, and to a lesser extent, the santa box. This is just a guess. Not even a theory because I have no solid data to back it up. It's just an observation I have been doing.
