The World of Warcraft: Classic team has posted a lengthy article on the official forum to lay out the initial details about how itemization will work. "The aim is to create a progression experience that resembles the original arc from when WoW first launched." While some items "progressed" from one patch to another (example: Helm of Wrath), that will not be the case when Classic arrives. Items will retain the stats they arrive with.
However, players of the original game found that when new things were added to the loot tables, there was "a deliberate effort to provide catch-up gear and/or to provide new goals for players who had exhausted an existing reward structure". The post further clarifies that this also happened with the progression of some skills in the original. That, however, will not be the case with Classic. All items will be set to v1.12, though the loot tables will still reflect the original roll out as new content is added over time (similar to the roll out of raids and dungeons).
Interestingly, the post then speaks about community building so that players aren't "constantly trying to figure out what we might do next to remain exactly in line with how the game once played out".
Recreating, and then re-fixing every major progression-affecting bug wouldn’t account for what we think matters much more: the people playing the game. There were many unknowns in original WoW. The first guilds to reach Nefarian spent their initial pulls testing different ideas they had and trying to figure out what condition would get them past the first part of the fight (defeating 40 drakonids). That experience can’t be recreated, because the knowledge can’t be unlearned. For a long time after Patch 1.4.0 came out, many players simply had no idea how good Obsidian Edged Blade or Aged Core Leather Gloves were. The power of weapon skill will be no surprise in WoW Classic.
So rather than try to recreate a specific experience from 2005 that can never fully be recaptured, our aim has been to accurately and fully restore the original game’s mechanics and stats to their final and most polished state from before The Burning Crusade. That mission has been a pillar of WoW Classic’s design from its inception.
This means that while content will be unlocked progressively to allow for each raid tier to shine, systems such as class design, battleground mechanics, and stats on existing items will all be set to their final 1.12 conditions. That should take the pressure off players to be constantly figuring out what we might do next to remain exactly in line with how the game once played out, and we can all focus a little more on community building and enjoying the experience together.
Read the full post on the World of Warcraft: Classic forum.