Maintenance for the week of April 15:
• [COMPLETE] ESO Store and Account System for maintenance – April 16, 8:00AM EDT (12:00 UTC) - 6:00PM EDT (22:00 UTC)
Yes, but since they held a lot of level III items I figured they would hold level III items when / if I returned ... even if the item in a particular barrel was different, they probably are programmed to contain the same level of items.