Blizzard has announced an upcoming major change to Horadric Cache loot.
In a future patch, Horadric Caches will be able to drop Torment-Only Legendaries.
The increased legendary drop rate will apply to all Legendaries that can be contained within the caches, which includes the Horadric Cache Legendaries and Torment-Only Legendaries. At this time it sounds as if the caches will contain only those two types, and not just any Legendary in the game, which is good!
The Horadric Cache loot will become that much sweeter, and this change will undoubtedly give us all the more reason to farm bounties on T1 and above.
This change is going to be implemented in Patch 2.0.5, which is going to be a balance pass / bug fix patch. As of right now, there is no ETA for 2.0.5.
Quote from Grimiku
As a heads up, we’re looking to make two changes to Horadric Caches. The first change is to allow the caches to drop Torment-only Legendary items. The second is to increase the chance that you’ll find a Legendary item in Horadric Caches, including Act-specific Legendaries like the Royal Ring of Grandeur, based on the Torment difficulty. What this means is that Horadric Caches earned in Torment I+ will be able to drop Torment restricted Legendary items, and caches earned in Torment II+ will have a scaling bonus for dropping Legendary items (which includes those items only found in a cache). (Source)