Igor that would incline people not to play the game but just buy skins instead. It would still be a special event (if the events/passes were purchasable after) because you earn the chance to unlock everything for free.
The game just needs to be free to play because how long or how much you need to play to unlock all the stuff in the event is almost undoable. Like I almost have every challenge finished and everything unlocked. Game just feels dry, it would feel better with free play so it can make more money and we can finally get some new maps (Ring of Garfat didnt need to set players on fire outside of the ring) lets hope they add new game soon!
Right now, I am force to spend time and money to earn the exclusive skins within reasonable play time for these events. Not having an event kills the game for the time being. So, until this game can go free to play and always have an event going with these ideas might be a good option.