They can still update current systems (non RF, challenge or unchained) to give atlantean shards in addition. Especially if they want to have these shards as kind of "activity" or "loyality" currency. Or, if they would have to update each mob and loot list for this, they can just add conversion npc or crafting recipes, so that players can craft these shards with standard drops. They can also still add crafting challenges and recipes...at the very least when they update the broken gem slots in the new rings (it is a shame that obsolete and broken items are advertised and given as end game power items. Either convert the slots to working ones or remove them!). They could do still so much, if they only were allowed to or wanted to.