In my opinion PvE and PvP in mmorpgs should never cross. Why not make 2 instances, one with PvP option and the one without it? So that 600 people can enter (as much as folks laugh about the game being dead, the playerbase is way bigger than 300 people) and farm all they want.
There's already a catastrophic situation with the amount of new/returning players. This event will only make it worse, since it caters only to a specific layer of players i.e. whales.