In the past, heirlooms used to be Bound To Battle.net Account and would not change. This would allow you to fully enchant a set and use it multiple times.
Now, if you equip any heirloom (some enchants make it soulbound without equipping it), it will become soulbound which.
Thanks for your feedback on Heirlooms! We originally planned to convert heirlooms to be Warbound until equipped to keep gear consistently using the new bind type. Upon further consideration, we’d like to continue to support the playstyle of setting up heirlooms with enchants and gems, then passing them to alts as needed. Given the 11.0.0 patch is today, we can’t easily fix this in the current patch, but it will be changed back in the upcoming 11.0.2 patch.
While unfortunately your gear will become bound if you enchant/equip until the next patch, once it comes out, your heirloom gear will revert to Warbound, allowing you to again pass it between alts after equipping / enchanting it. We apologize for the temporary inconvenience and again, thank you so much for the feedback.
-Drough
