https://wccftech.com/wow-classic-itemization-detailed/

Blizzard has provided additional details on itemization in World of Warcraft’s upcoming vanilla server option, WoW Classic.

Community manager Aerythlea released the additional info in a new post on the official WoW forums over the weekend. Like other elements in Classic, items will be based on Blizzard’s reference version for Classic, patch 1.12. Blizzard notes that while content will be unlocked in phases, systems such as class design, battleground mechanics, and stats on existing items will all be based on patch 1.12.