Yes. When game maps re-load, non-unique loot drops also re-load. That means most chests will have new stuff to find. Rare items might not drop the first through a dungeon. For early game stuff, that's not too bad because the odds are the next dungeon will have equal or better stuff. But at the end game, you really do want to run those dungeons a few times to get the end game equipment.
You can tell if the Arc chests reset because the enemies all the enemies will respawn. Note, the self-repairing ones will repair and pop up so don;t use them to indicate if a map reset.