Are you suggesting the recipient found another Activation Locked laptop, presumably stolen, that somebody was keeping "for parts", swapped the keyboard for a Japanese keyboard, sent OP that locked laptop and wiped/kept their laptop?
Considering how long it took for the laptop to be returned and Apple's resistance in removing the lock, it is possible that the recipient waited until an acquaintance returned from Japan carrying a similar laptop (acquired cheaply or even for free due to the lock), and simply shipped that to OP.
