Hello Pants
This is what I got from the Raid Boss team.
"The TKR-1001 boss is a little different from previous ones in that this event is split into 3 stages. This current event is Stage 1. Stage 2 will be next week, and Stage 3 will be the week after. Also the loot threshold for this boss was lowered, making the chances to get loot items much better then in previous bosses.
Our team is reviewing this event’s performance closely and will adjust the next stages accordingly."