So no one saw this coming?
It was either gonna be Brooks, Shanks, Judge or the guy from Lost who was pulled from the schedule a few days before.
This happens before every SM event. They show everyone a nice full lineup, sell loads of gold and advance tickets before cancelling one or more of the major guests who all those ticket holders have paid to see.
No one can get refunds on their event and or train/bus tickets, so most of them will still go to the event and pay to get in regardless of there being no guests that they want to see.