In between festivals and special weekend events, I think it would be great if the devs introduced map meta weeks where the focus is placed on a single map meta each week, with special rewards such as a common currency to be used for special weapon/armor skins, etc. Each week, the meta focus will rotate to another meta. They could either put a cap on the currency so that it wouldn't be possible to get all of the items in one week, or they could introduce new items/skins with each week. For instance, you could have Augry Rock one week followed by Maws of Torment the next week. I think this would help bring players back to some of the older metas, which will also help new players out who have never done them, and who sometimes come into pretty empty maps. This wouldn't have to be limited to just the major map metas, so you could have community bounty hunts, and other event chain hunts. Sure, many of the metas do get done, but I think with so many metas to do, players are getting spread thinly among them these days.