https://www.mmo-champion.com/conten...ft-in-the-New-Year-Patch-6-1-Heirloom-Changes That's just cuz heirlooms had a rework in 6.1. https://www.wowhead.com/achievement=6626/working-better-as-a-team Heirloom legs come from a guild achievement added in MoP tho.