EDIT: This is still an issue for Songflower and ZG buff. Otherwise the rest of the buffs appear to work as described in the blue post update on the 26th of Nov.
Chronoboon Displacer
Items that share exclusivity with world buffs (Horn of the Dawn, Songflower Seed, Shimmering Globe, Overseer’s Anvil, “Defective” Magic 8-Ball, Firewater Cauldron (stacking change only), and Spirit Conch): Will no longer be removed if the person with the consumable leaves raid. Will extend the duration of the appropriate world buff instead of replacing it. Now stack up to 5. Known issue: these consumable items list their duration as Until Cancelled instead of 1 or 2 hours. That will be corrected in another hotfix.
Currently if somebody uses one of the new consumable world buffs, it will delete your booned buff and you receive a non-boonable version of it. It will also only last as long as the user is in group.
We just experienced someone using defective magic 8 ball (DMF) and songflower seed (Songflower) consume for some reason and left early in the raid effectively overwriting and deleting it from the raid.
This also means anyone can grief a party or raid by spamming buffs and leaving, effectively forcing up to 39 people to re-gather all their world buffs which is the timely activity this addition was meant to resolve.