I've seen similar threads in the past few days leading up to the release of the patch, and while I believed that they were going to provide all four chests for each party at the end of the instance, the fact is that each boss drops a chest right after completion. I knew something was fishy when one of our DPS asked everyone else to pass DRG stuff for him (he was on Dragoon and the only one in the party, anyway??), but when the first chest popped, BRD boots appeared. He greeded them, it dropped to him, he vanished.