I have seen where it was stated that world loot drops would be fixed. See thread here for some of the most recent discussions:
https://forum-en.gw2archive.eu/forum/support/bugs/No-Loot-From-Champions/first#post1072872
Back in Nov the update notes specifically stated they were doing something about the world loot drops. Here is the link to those notes:
https://forum-en.gw2archive.eu/forum/info/news/Game-Update-Notes-November-15-2012/first#post744278
Still not fixed. Why?