If dying in SAO secretly didn't mean death in real life?

What I mean is Kayaba tells the players they will die in game but actually they would be placed in an of the map location and then respawn as NPCs mobs (with mob restrictions so they don't enter safe zones and the like and fight other mobs and players) for the rest of the game. Off course if the Nervegear is removed then a player does die but otherwise no. Yui would be used for the players here, the "dead" players I mean. Remember the "living" fight for their life so their personality development wouldn't change much. How would this change the story?