[Mind-numbed Robot]

This probably answers the questions about the sudden departure of a top general in NK. Even if the Great Leader planned this the general could be a sacrificial lamb.

[TigerLikesRooster]

This is one of the theories floating around in SK, while prevailing local consensus is that he was kicked out to make room for designated successor's crony.

However, since such public announcement of sacking is pretty unusual, something terrible may be waiting for him.