Original Post — Direct link
Most bosses in the game, along with reward chests from arenas and incursions, will now preferentially drop set items that have not yet been unlocked in your Item Set Collections.

Hurray!
Well that was fairly inevitable, but still: hurray! May I'll get that Medusa inferno staff now.

But wait deos that mean...
dellve bosses have curated drops?
Do all public dungeon bosses have it, or just the group event boss?
Do world bosses have it?
Do all dungeon bosses have it or just the final one?
Do all trial bosses have it or just the final one?

@ZOS_GinaBruno could you please clarify for us?
over 2 years ago - ZOS_Finn - Direct link
The goal was to make content that players engage in for specific rewards more rewarding the more it is completed. So, Delve bosses, Public Dungeon champions, Group Bosses in overland would all have curation. Same with Dungeons and Trials, it will be included for all bosses.

One thing to note is, we are not adding drops to monsters that do not currently drop a specific piece of gear. So, if the monster only dropped legs and shoulders, it will continue to only drop those and just use curation to determine which pieces you would get from that list.