Halls and those others mentioned are dropping socket upgrades due to a bug when they made them mythic, you dont run them in mythic. As far as I know, those do not upgrade to epic..... yet. WoD is the only one that upgrades epic.
On the beta, i was getting socket and tertiary upgrades from TBC dungeons.... but that has not happened on live.
SO right now, WoD is the place to get epic/tert/socket upgrades. If you're 25-29 you can run 4 of the WotLK that drop epic loot but those wont upgrade. On the beta that WotLK loot has been changed to blue in the adventure journal but is still epic if you copy over with it. Like i said..... not sure wtf is going on, just trying to do what we can.
edit- ALSO... its dungeon epics that scale highest. Not quest rewards, not world drops... dungeons drops. Makes no sense so hopefully it's just typical broken blizz shit an all epic, green and rare ilvl will be the same.