There are NPCs here too?
Yes. Yes there are!
It might seem a bit surprising, given the format change, but here they certainly are, just as always. There will be a couple who turn up as extra participants, perhaps as expected. They work much the same as always: they will have a handicap ranging from 1 to 5 which determines their general 'quality', with higher being better. This affects several things, not the least of which is their overall threat or danger level in a combat situation.
NPC contestants will also have their own roles, just like normal players, and depending on their handicap may have some other special quirks or tricks to them outside of the norm.
Beyond the expected NPC participants, however, there are some other tricks and surprises at play! There will be a great many others at play, as events will reveal to you soon after the event starts. And once you get underway and begin exploring, you might just run across even more. After all, what are the chances of everyone you run into out there being hostile?