This idea is awesome! Make tge world breath. Could be done server side, this wouldcmake stuff way better, there r events similar to what u described, though they do not affect the world around us once ur done. These events start an all out war between two factions in a given area when eventually hords of ultras bliz your ass. You dont get a thing from bearing through these but they are cool and fun to be in. Also a dungeon type mission with daily or weekly loot cycles (for materials ) was suggested a couple of days ago. These could be random generated creep spawns or rooms, with increased lvl for each wave. These would make spending time in this world bungie created way more fun.